CLASS 12TH CHAPTER -8 Human Health and Disease |NCERT BIOLOGY SOLUTIONS | EDUGROWN

Class 12 biology sets a strong basis for advanced studies. Subject experts clear all your queries during exam preparation by the explanation of the solutions in a conceptual way.

All chapter class 12 Biology NCERT Solutions are prescribed by the subject teachers based on the NCERT textbook questions and explained all solutions in a better way for easy understanding. In-depth knowledge of the biology subject can be attained by the students with the help of detailed NCERT Solutions of Class 12 Biology

NCERT Solutions for Class 12 Biology Chapter : 8 Human Health and Disease

Page No: 164
 
Exercises

Question 1.
What are the various public health measures, which you would suggest as a safeguard against infectious diseases?
Solution:
Prevention and control of infectious diseases

I. For water-borne diseases like typhoid, amoebiasis, etc.
Practice personal and public hygienic measures.

a. Personal hygienic measures

  • Keeping the body clean
  • Consumption of clean drinking water
  • Eating fresh food

b. Public hygienic measures

  • Proper disposal of waste and excreta
  • Periodic cleaning and disinfection of water reservoirs, pool, tank etc.

II. For air-borne diseases like common cold, pneumonia

  • Avoid close contact with infected persons.
  • Avoid the use of belongings of the infected persons.

III. For vector-borne diseases like malaria

  • Control and eliminate the vectors and their breeding places
  • Introducing larvivorous fishes like Gambusia in ponds that feed on the larvae of the mosquito
  • Avoid stagnation of water around the residential area.
  • Spraying of insecticides in ditches, drainage areas, etc.
  • Protection from a mosquito bite. Use mosquito nets in the doors and windows to prevent the entry of mosquitoes. It is very important in the light of recently widespread diseases like dengue fever, chikungunya etc.

The use of vaccines and immunization programmes has enabled us to eradicate smallpox. Diseases like polio, diphtheria, tetanus etc. have been controlled to an extent by the use of vaccines. Nowadays biotechnology is focussing on the preparation of newer and safer vaccines. A large number of antibiotics are available to treat many infectious diseases.

2. In which way has the study of biology helped us to control infectious diseases?

Answer

→ Various advancements that have occurred in the field of biology have helped us gain a better understanding to fight against various infectious diseases.
→ Biology has developed as we have come to know about the life cycle of various parasites, pathogens, and vectors along with the modes of transmission of various diseases and the measures for controlling them.


→ Vaccination programmes against several infectious diseases such as small pox, chicken pox, tuberculosis, etc. have helps us to eradicate these diseases.
→ Biotechnology has helped in the preparation of developed and safe drugs and vaccines.
→ Antibiotics have also played  a major role in  the treatment of various infectious diseases.

3. How does the transmission of each of the following diseases take place?
(a) Amoebiasis          (b) Malaria           (c) Ascariasis         (d) Pneumonia

Answer

(a) Amoebiasis: It is a vector transmitted disease that spreads by the means of contaminated food and water. The vector involved in the transmission of this disease is the housefly. Its mode of transmission is Entamoeba histolytica.

(b) Malaria: It is a vector transmitted disease that spreads by the biting of the female Anopheles mosquito. Its mode of transmission is Ascaris lumbricoides.



(c) Ascariasis: It spreads through contaminated food and water. Its mode of transmission is Ascaris lumbricoides

(d) Pneumonia: It spreads by the sputum of a diseased  person. Its mode of transmission is Streptococcus pneumoniae,

Question 4.
What measure would you take to prevent water-borne diseases?
Solution:
Water-borne diseases can be prevented by drinking clean water. Water should be free from contamination, suspended and dissolved substances. If water is contaminated it should be boiled and filtered before drinking. Periodic cleaning and disinfection of water reservoirs, pools, and tanks should be done.

Question 5.
Discuss with your teacher what does ‘a suitable gene’ means, in the context of DNA vaccines.
Solution:
‘A suitable gene’ means the gene which is able to produce antigenic polypeptides of the pathogen in bacteria and yeast. Using recombinant DNA technology, it is possible to produce vaccines in large scale for immunisation. Hepatitis B vaccine is produced using this technology.

Question 6.
Name the primary and secondary lymphoid organs.
Solution:
Primary lymphoid organs are bone marrow and thymus. Secondary lymphoid organs are the spleen, lymph nodes, tonsils, Peyer’s patches of the small intestine, and mucosa-associated lymphoid tissues (MALT).

Question 7.
The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form.

  1. MALT
  2. CMI
  3. AIDS
  4. NACO
  5. HIV

Solution:

  1. MALT – Mucosal-associated lymphoid tissue.
  2. CMI – Cell-Mediated Immunity
  3. AIDS – Acquired Immuno Deficiency Syndrome
  4. NACO – National AIDS Control Organisation
  5. HIV – Human immunodeficiency virus.
8. Differentiate the following and give examples of each:
(a) Innate and acquired immunity    (b) Active and passive immunity

Answer

(a) Innate and acquired immunity

Innate immunityAcquired immunity
(i) It is a non-pathogen specific type of defense mechanism.(i) It is a pathogen specific type of defense mechanism.
(ii) It is inherited from parents and protects the individual since birth.(ii) It is acquired after the birth of an individual.
(iii) It operates by providing barriers against the entry of  pathogenic  agents.(iii) It produces primary and secondary responses, which are mediated by B-lymphocytes and T-lymphocytes.
(iv) It does not  specific memory.(iv) It is observed by an immunological memory.

(b) Active and passive immunity

Active immunityPassive immunity
(i) It is a type of acquired immunity in which the body produces its own antibodies against disease-causing antigens.(i) It is a type of acquired immunity in which readymade antibodies are transferred from one person to another.
(ii) It shows long lasting effect.(ii) It does not have long lasting effect.
(iii)It is slow. It takes time in producing antibodies and giving responses.(iii) It is fast. It provides immediate respose.
(iv) Injecting microbes through vaccination inside the body is an example of active immunity.(iv) Transfer of antibodies present in the mother’s milk to the infant is an example of passive immunity.

9. Draw a well-labelled diagram of an antibody molecule.

Answer

10. What are the various routes by which transmission of human immuno-deficiency virus takes place?

Answer

AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immunodeficiency virus (HIV).
This is transmitted by following modes –
(a) Unprotected sexual contact with a diseased  person.
(b) Transfusion of blood from a healthy to a diseased person.
(c) Sharing infected needles or syringes.
(d)  infected mother to a child through the placental connection.

11. What is the mechanism by which the AIDS virus causes deficiency of immune system of the infected person?

Answer

→ AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immunodeficiency virus (HIV) via sexual or blood to blood contact.
→ After entering the human body, the HIV virus attacks and enters into the macrophages. Inside the macrophages, the RNA of the virus replicates with the help of enzyme reverse transcriptase and gives  rise to viral DNA copy.
→ Then, this viral DNA incorporates into the host DNA and directs the synthesis of virus particles. → At the same time, HIV enters helper T- lymphocytes. It replicates and produces viral progeny.
→ These newly formed progeny viruses get released into the blood, attacking other healthy helper T-lymphocytes in the body.
→ As a result, the number of T-lymphocytes in the body of an infected person decreases  in number, which causes decrease in  immunity of person.

12. How is a cancerous cell different from a normal cell?

Answer

Normal cellCancerous cell
(i) Normal cells show the property of contact inhibition. Therefore, when these cells come into contact with other cells, they stop dividing.(i) Cancerous cells lack the property of contact inhibition. Therefore, they continue to divide, thereby forming a mass of cells called tumor.
(ii) They undergo differentiation after attaining a specific growth.(ii) They do not undergo differentiation.
(iii) These cells remain confined at a particular location.(iii) These cells do not remain confined at a particular location. They move into neighboring tissues and disturbs the functioning.

13. Explain what is meant by metastasis.

Answer

The property of metastasis is perfomed by malignant tumors. These melingnent cells moves through different part of body by a pathological process. These cells divide uncontrollably, forming a mass of cells called tumor. From the tumor, some cells get shed off and enter into the blood stream. From the blood stream, these cells reach distant parts of the body and therefore, start the formation of new tumors by dividing actively.

14. List the harmful effects caused by alcohol/drug abuse.

Answer

Alcohol and drugs have several adverse effects on the individual, his family, and the society.
(i) Effects of alcohol:
→ Effects on the individual: Alcohol is injurious to the health of the individual. When an individual consumes excess alcohol, it causes damage to the liver and the central  nervous system. As a result, other symptoms such as depression, fatigue, aggression, loss of weight and appetite may also be observed in the individual. Sometimes, extreme levels of alcohol consumption may also lead to heart failure, resulting coma and death. The immediate adverse effects of alcohol abuse are manifested in form of reckless bhehaviour, vandalism and voilence,Also, it is advisable for pregnant women to avoid alcohol as it may inhibit normal growth of the baby.
→ Effects on the family: Consumption of excess alcohol by any family member can have devastating effects on the family. It leads to several domestic problems such as quarrels, frustrations, insecurity, etc.
Effects of alcohol on society-
(a) Rash behaviour
(b) Malicious mischief and violence
(c) Disturbing social network
(d) Loss of interest in social activities, loss of interests in hobbies,change in eating and sleeping habites etc.

(ii) Effects of drugs: An individual who is addicted to drugs creates problems not only for himself but also for his family.
→ Effects on the  addited individual: Drugs have an adverse effect on the central nervous system of an individual. This leads to the malfunctioning of several other organs of the body such as the kidney, liver, etc. The spread of HIV is most common in these individuals as they share common needles while injecting drugs in their body. Drugs have long-term side effects on both males and females. These side effects include increased aggressiveness, mood swings, and depression
→ Effects on the family and society: A person addicted to drugs creates problems for his family and society. A person dependant on drugs becomes frustrated, irritated, and anti-social.At the time of drug addicted becomes mental and financial distress.

15. Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?

Answer

Yes, friends can influence one to take drugs and alcohol. A person can take the following steps for the prevention of themself  against drug abuse:
→ by avoiding undue peer pressur as everyone has theire own field of  interest which shouid be respected by theire teachers and family. One should not experiment with alcohol for curiosity and fun.
→ Avoid the company of friends who take drugs.
→ Seek help from parents and peers.a child should not pushed beyond his/her threshold limits.
→ Take proper knowledge and counseling about drug abuse. Devote your energy in other extra-curricular activities.
→ Seek immediate professional and medical help from psychologists and psychiatrists if symptoms of depression and frustration become apparent.
→ Get rid of the problems completely and lead a perfectly normal life by increasing their will power.

16. Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.

Answer

This question should be discussed with your subject teacher.

17. In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided?

Answer

→ Various factors are responsible for motivating youngsters towards alcohol or drugs. Curiosity, need for adventure and excitement, experimentation  for fun are the initial causes for motivating youngsters.
→ Some youngsters start consuming drugs and alcohol in order to overcome negative emotions (such as stress, pressure, depression, frustration) and to excel in various fields..such youngsters use to abuse alcohol due to their family pressure for academics .
→ Several mediums like television, internet, newspaper, movies promote various brend by the brand ambassadors like celebrities . Celebrities are also ideal of youngsters so the get much infiuenced by them.
→ Amongst these factors, reasons such as unstable and unsupportive family structures and peer pressure can also lead an individual to be dependant on drugs and alcohol.
Preventive measures against addiction of alcohol and drugs:
(i) Parents should motivate and try to increase the will power of their child.
(ii) Parents should educate their children about the ill-effects of alcohol. They should provide them with proper knowledge and counselling regarding the consequences of addiction to alcohol.
(iii) It is the responsibility of the parent to discourage a child from experimenting with alcohol. Youngsters should be kept away from the company of friends who consume drugs.
(iv) Children should be encouraged to devote their energy in other extra- curricular and recreational activities.
(v) Proper professional and medical help should be provided to a child if sudden symptoms of depression and frustration are observed.
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CLASS 12TH CHAPTER – 7 Evolution |NCERT BIOLOGY SOLUTIONS | EDUGROWN

Class 12 biology sets a strong basis for advanced studies. Subject experts clear all your queries during exam preparation by the explanation of the solutions in a conceptual way.

All chapter class 12 Biology NCERT Solutions are prescribed by the subject teachers based on the NCERT textbook questions and explained all solutions in a better way for easy understanding. In-depth knowledge of the biology subject can be attained by the students with the help of detailed NCERT Solutions of Class 12 Biology

NCERT Solutions for Class 12 Biology Chapter : 7 Evolution

Page No: 142
 
Exercises
 
1. Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
 
Answer
 
In the presence of antibiotic, the bacteria that are sensitive to it will die. However, if there are any mutants in the population, that can somehow survive its effect, they will multiply and increase in numbers. After that, they will live as antibiotic resistant bacteria.
 

Question 2.
Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
Solution:
Chimps are more evolved than humans (The Times of India):
Chimpanzees are more evolved than humans, a study suggests. There is no doubt that humans are the more advanced species. But a comparison of 14,000 human and chimpanzee genes shows the forces of natural selection have and the greatest impact on our ape cousins.

The researchers’ discovery challenges the common assumption that our large brains and high intelligence were the gifts of natural selection. Humans and chimps followed different evolutionary paths from a common ape ancestor about 5 million years ago. Both underwent changes as the fittest survived to pass their genes on to future generations. But the US study shows that humans possess a ‘substantially smaller’ number of positively-selected genes than chimps.

Question 3.
Attempt giving a clear definition of the term species.
Solution:
A species generally includes a similar organism. Members of this group can show interbreeding. A similar group of genes are found in the members of the same species and this group has the capacity to produce new species. Every species has some cause of isolation which interrupted the interbreeding with the nearest reactional species which is referred to as reproductively isolated.

Question 4.
Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)
Solution:Answer

Human evolution shows the following trends:
A. Brain size: It increased gradually along with evolution. The brain capacity of Australopithecus africanus – 500 cc, Homo habilis – 700 cc, Homo eredus – 800 – 1300 cc, Homo sapiens sapiens – 1450 cc.

B. Skeletal structure:

NameFeatures
DryopithecusApe like, canines large, arms and legs are of equal size, ate soft fruits and leaves
RamapithecusMore man-like, canines were small while molars were large, walked more erect, ate seeds and nuts
Australopithecus Man-like, canines and incisors were small, walked upright, hunted with stone weapons, ate fruits, brain capacities were between 400-600cc.
Homo habilisFirst human like being, canines were small, first tool makers, did not ate meats, brain capacities were between 650-800cc. 
Homo erectusUsed stone and bone tools for hunting games, ate meat, brain capacity 900cc.
Homo neanderthalnsisCave dwellers, used hides to protect their bodies, and buried their dead, brain capacity 1400cc.
Homo sapiens (Modern human)Modern man with high intelligence, developed art, culture, language etc., cultivated crops and domesticated animals.


Question 5.

Find out through the internet and popular science articles whether animals other than man have self-consciousness.
Solution:
There are many animals other than humans, which have self-consciousness. An example of an animal being self-conscious is dolphins. They are highly intelligent. They have a sense of self and, they also recognize others among themselves and others. They communicate with each other by whistles, tail-slapping, and other body movements, not dolphins, there are certain other animals such as Crow, Parrot, chimpanzees, Gorilla, Orangutan, etc., which exhibit self-consciousness.

Question 6.
List 5-6 modern-day animals and using the internet resources link it to a corresponding ancient fossil. Name both.
Solution:
The list of few modern-day animals and their corresponding ancient fossils is as follows:
NCERT Solutions for Class 12 Biology Chapter 7 Evolution Q6.1
NCERT Solutions for Class 12 Biology Chapter 7 Evolution Q6.2
NCERT Solutions for Class 12 Biology Chapter 7 Evolution Q6.3

Question 7.
Describe one example of adaptive radiation.
Solution:
Adaptive radiation – Formation of different species from a common ancestor with new species adapting to different geological niches.
Example: Darwin’s finches are Galapagos island have wolves from mainland finches. They underwent changes in the shape, size of beaks, food habits, feathers.

Question 8.
Can we call human evolution adaptive radiation?
Solution:
No, we can not be called human evolution as adaptive evolution.

Question 9.
Using various resources such as your school library or the Internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.
Solution:
The evolutionary stages of the modern horse are listed in the table given below:
NCERT Solutions for Class 12 Biology Chapter 7 Evolution Q9.1

• Eohippus: It appeared in the Eocene period about 52 million years ago. It was approximately the size of a fox (0.4 m), with a relatively short head and neck and a springy, arched back. It had four functional toes and a splint of 1 and 5 on each hind limb and a splint of 1 and 3 in each forelimb.

• Mesohippus: Approx, 40 million years ago in Oligocene period, Mesohippus which was slightly larger than Eohippus about 0.6 metre. It had three toes in each foot.

• Merychippus: In Miocene period the grazer Merychippus flourished. It had the size of approx 1m. It still had three toes in each foot, but it could run on one toe. The side toe did not touch the ground. The molars were adapted for chewing the grass.

• Pliohippus: Around 12 million years in Pilocene period, modern horse Pilohippus emerged. It had a single functional toe with splint of 2nd and 4th in each limb.

• Equus: Pliohippus gave rise to modern horse, Equus. It have one toe in each foot. They have incisors for cutting grass and molars for grinding food.

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NCERT MCQ CLASS-11 CHAPTER-8 | MATH NCERT MCQ | BINOMIAL THEOREM| EDUGROWN

In This Post we are  providing Chapter-8 Binomial Theorem NCERT MCQ for Class 11 Math which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON BINOMIAL THEOREM

Question 1.
The coefficient of y in the expansion of (y² + c/y)5 is

(a) 10c
(b) 10c²
(c) 10c³
(d) None of these

Answer: (c) 10c³

Question 2:
(1.1)10000 is _____ 1000

(a) greater than
(b) less than
(c) equal to
(d) None of these

Answer: (a) greater than

Question 3.
The fourth term in the expansion (x – 2y)12 is

(a) -1670 x9 × y³
(b) -7160 x9 × y³
(c) -1760 x9 × y³
(d) -1607 x9 × y³

Answer: (c) -1760 x9 × y³

Question 4.
If n is a positive integer, then (√3+1)2n+1 + (√3−1)2n+1 is
(a) an even positive integer
(b) a rational number
(c) an odd positive integer
(d) an irrational number

Answer: (d) an irrational number

Question 5.
If the third term in the binomial expansion of (1 + x)m is (-1/8)x² then the rational value of m is
(a) 2
(b) 1/2
(c) 3
(d) 4

Answer: (b) 1/2

Question 6.
The greatest coefficient in the expansion of (1 + x)10 is

(a) 10!/(5!)
(b) 10!/(5!)²
(c) 10!/(5! × 4!)²
(d) 10!/(5! × 4!)

Answer: (b) 10!/(5!)²

Question 7.
The coefficient of xn in the expansion of (1 – 2x + 3x² – 4x³ + ……..)-n is

(a) (2n)!/n!
(b) (2n)!/(n!)²
(c) (2n)!/{2×(n!)²}
(d) None of these

Answer: (b) (2n)!/(n!)²

Question 8.
The value of n in the expansion of (a + b)n
 if the first three terms of the expansion are 729, 7290 and 30375, respectively is
(a) 2
(b) 4
(c) 6
(d) 8

Answer: (c) 6

Question 9.
If α and β are the roots of the equation x² – x + 1 = 0 then the value of α2009 + β2009 is

(a) 0
(b) 1
(c) -1
(d) 10

Answer: (b) 1

Question 10.
The general term of the expansion (a + b)n is

(a) Tr+1 = nCr × ar × br
(b) Tr+1 = nCr × ar × bn-r
(c) Tr+1 = nCr × an-r × bn-r
(d) Tr+1 = nCr × an-r × br

Answer: (d) Tr+1 = nCr × an-r × br

Question 11.
The coefficient of xn in the expansion (1 + x + x² + …..)-n is

(a) 1
(b) (-1)n
(c) n
(d) n+1

Answer: (b) (-1)n

Question 12.
If n is a positive integer, then (√5+1)2n + 1 − (√5−1)2n + 1 is

(a) an odd positive integer
(b) not an integer
(c) none of these
(d) an even positive integer

Answer: (b) not an integer

Question 13.
In the expansion of (a + b)n, if n is even then the
middle term is
(a) (n/2 + 1)th term
(b) (n/2)th term
(c) nth term
(d) (n/2 – 1)th term

Answer: (a) (n/2 + 1)th term

Question 14.
In the expansion of (a + b)n, if n is odd then the number of middle term is/are
(a) 0
(b) 1
(c) 2
(d) More than 2

Answer: (c) 2

Question 15.
if n is a positive integer then 23nn – 7n – 1 is divisible by

(a) 7
(b) 9
(c) 49
(d) 81

Answer: (c) 49



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NCERT MCQ CLASS-11 CHAPTER-7 | MATH NCERT MCQ | PERMUTATIONS AND COMBINATIONS | EDUGROWN

In This Post we are  providing Chapter-7 Permutations and Combinations NCERT MCQ for Class 11 Math which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON PERMUTATIONS AND COMBINATIONS

Question 1. In how many ways can a consonants and a vowel be chosen out of the word COURAGE?
(a) 7C2
(b) 7P2
(c) 4P1× 3P1
(d) 4P13P1

Answer :   C

Question 2. How many words can be formed from the letters of the word DOGMATIC, if all the vowels remain together :
(a) 4140
(b) 4320
(c) 432
(d) 43

Answer :  B

Question 3. Numbers lying between 999 and 10000 than can be formed from the digits 0, 2, 3, 6, 7, 8 (repetition of digits not allowed) are :
(a) 100
(b) 200
(c) 300
(d) 400

Answer :  C

Question 4. How many numbers of 6 digits can be formed from the digits of the number 112233?
(a) 30
(b) 60
(c) 90
(d) 120

Answer :  C


Question 5. The sum of all five digit numbers that can be formed using the digits 1, 2, 3, 4, 5 when repetition of digits is not allowed, is
(a) 366000
(b) 660000
(c) 360000
(d) 3999960

Answer :  D

Question 6. How many 10 digit numbers can be written by using the digits 1 and 2 :
(a) 10C1 + 9C2
(b) 210
(c) 10C2
(d) 10!

Answer :  B

Question 7. In a test there were n questions. In the test 2n – i students gave wrong answers to i questions i = 1, 2, 3, ……..n. If the total number of wrong answers given is 2047 then n is
(a) 12
(b) 11
(c) 10
(d) None of these

Answer :  C

Question 8. A set contains (2n + 1) elements. If the number of subsets of this set which contain at most n elements is 4096, then the value of n is
(a) 6
(b) 15
(c) 21
(d) None of these

Answer :  D

Question 9. The number of numbers of 9 different non-zero digits such that all the digits in the first four places are less than the digit in the middle and all the digits in the last four places are greater than the digit in the middle is
(a) 2 (4 !)
(b) (4 !) 2
(c) 8 !
(d) None of these

Answer :  B

Question 10. The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of three parallel lines:
(a) 6
(b) 9
(c) 18
(d) 12

Answer :  C

Question 11. Ten different letters of an alphabet are given, words with five letters are formed. The number of words which at least one letter repeated is :
(a) 69760
(b) 30240
(c) 99748
(d) 37120

Answer :  A

Question 12. There are 10 points in a plane, out of which 4 points are collinear. The number of triangles formed with vertices as there points is:
(a) 20
(b) 120
(c) 40
(d) 116

Answer :  D

Question 13. In a college of 300 students, every student read 5 newspapers and every newspaper is read by 60 students. The number of newspaper is:
(a) at least 30
(b) at most 20
(c) exactly 25
(d) none of these

Answer :  C

Question 14. The number of ways in which 6 rings can be worn on four fingers of one hand is :
(a) 46
(b) 6C4
(c) 64
(d) 24

Answer :  C

Question 15. In a chess tournament where the participants were to play one game with one another, two players fell ill having played 6 games each, without playing among themselves. If the total number of games is 117, then the number of participants at the beginning was :
(a) 15
(b) 16
(c) 17
(d) 18

Answer :  A


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NCERT MCQ CLASS-11 CHAPTER-6 | MATH NCERT MCQ | LINEAR INEQUALITIES| EDUGROWN

In This Post we are  providing Chapter-6 Linear Inequalities NCERT MCQ for Class 11 Math  which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON LINEAR INEQUALITIES

Question 1.
Sum of two rational numbers is ______ number.

(a) rational
(b) irrational
(c) Integer
(d) Both 1, 2 and 3

Answer: (a) rational

Question 2.
If x² = -4 then the value of x is

(a) (-2, 2)
(b) (-2, ∞)
(c) (2, ∞)
(d) No solution

Answer: (d) No solution

Question 3.
Solve: (x + 1)² + (x² + 3x + 2)² = 0

(a) x = -1, -2
(b) x = -1
(c) x = -2
(d) None of these

Answer: (b) x = -1

Question 4.
If (x + 3)/(x – 2) > 1/2 then x lies in the interval

(a) (-8, ∞)
(b) (8, ∞)
(c) (∞, -8)
(d) (∞, 8)

Answer: (a) (-8, ∞)

Question 5.
The region of the XOY-plane represented by the inequalities x ≥ 6, y ≥ 2, 2x + y ≤ 10 is

(a) unbounded
(b) a polygon
(c) none of these
(d) exterior of a triangle

Answer: (c) none of these

Question 6.
The interval in which f(x) = (x – 1) × (x – 2) × (x – 3) is negative is

(a) x > 2
(b) 2 < x and x < 1
(c) 2 < x < 1 and x < 3
(d) 2 < x < 3 and x < 1

Answer: (d) 2 < x < 3 and x < 1

Question 7.
If -2 < 2x – 1 < 2 then the value of x lies in the interval

(a) (1/2, 3/2)
(b) (-1/2, 3/2)
(c) (3/2, 1/2)
(d) (3/2, -1/2)

Answer: (b) (-1/2, 3/2)

Question 8.
The solution of the inequality |x – 1| < 2 is

(a) (1, ∞)
(b) (-1, 3)
(c) (1, -3)
(d) (∞, 1)

Answer: (b) (-1, 3)

Question 9.
If | x − 1| > 5, then

(a) x∈(−∞, −4)∪(6, ∞]
(b) x∈[6, ∞)
(c) x∈(6, ∞)
(d) x∈(−∞, −4)∪(6, ∞)Answer

Answer: (d) x∈(−∞, −4)∪(6, ∞)

Question 10.
The solution of |2/(x – 4)| > 1 where x ≠ 4 is

(a) (2, 6)
(b) (2, 4) ∪ (4, 6)
(c) (2, 4) ∪ (4, ∞)
(d) (-∞, 4) ∪ (4, 6)

Answer: (b) (2, 4) ∪ (4, 6)

Question 11.
If (|x| – 1)/(|x| – 2) ‎≥ 0, x ∈ R, x ‎± 2 then the interval of x is

(a) (-∞, -2) ∪ [-1, 1]
(b) [-1, 1] ∪ (2, ∞)
(c) (-∞, -2) ∪ (2, ∞)
(d) (-∞, -2) ∪ [-1, 1] ∪ (2, ∞)

Answer: (d) (-∞, -2) ∪ [-1, 1] ∪ (2, ∞)

Question 12.
The solution of the -12 < (4 -3x)/(-5) < 2 is

(a) 56/3 < x < 14/3
(b) -56/3 < x < -14/3
(c) 56/3 < x < -14/3
(d) -56/3 < x < 14/3

Answer: (d) -56/3 < x < 14

Question 13.
If x² = -4 then the value of x is

(a) (-2, 2)
(b) (-2, ∞)
(c) (2, ∞)
(d) No solution

Answer: (d) No solution

Question 14.
Solve: |x – 3| < 5

(a) (2, 8)
(b) (-2, 8)
(c) (8, 2)
(d) (8, -2)

Answer: (b) (-2, 8)

Question 15.
The graph of the inequations x ≥ 0, y ≥ 0, 3x + 4y ≤ 12 is

(a) none of these
(b) interior of a triangle including the points on the sides
(c) in the 2nd quadrant
(d) exterior of a triangle

Answer: (b) interior of a triangle including the points on the sides


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NCERT MCQ CLASS-11 CHAPTER-5 | MATH NCERT MCQ | COMPLEX NUMBERS AND QUADRATIC EQUATION | EDUGROWN

In This Post we are  providing Chapter-5 Complex Numbers and Quadratic Equation NCERT MCQ for Class 11 Math  which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON COMPLEX NUMBERS AND QUADRATIC EQUATION

1. Let Z1 = 10+ 6i and Z2 = 4+6i . If Z be a complex number such that    Then |Z – 7 -9i| =

(a) 3√2

(b) 4√2

(c) 2√2

(d) √2

Answer► (a) 3√2

2. The number of the integer solutions of x2 + 9 < (x + 3)2 < 8x + 25 is

(a) 1

(b) 2

(c) 3

(d) None of these

Answer► (d) None of these

3. If (a1 +ib1)(a2 +ib2) ….(an + ibn) = A +iB, then  is equal to

(a) 1

(b) (A2 + B2)

(c) (A + B)

(d) (1/A2 + 1/B2)

Answer► (b) (A2 + B2)

4. The set of all solutions of the inequality (1/2)x2-2x < 1/4 contains the set

(a) (–∞, 0)

(b) (–∞, 1)

(c) (1, ∞)

(d) (3, ∞)

Answer► (d) (3, ∞)

5. The number of solutions of the equation  is

(a) 2

(b) 3

(c) 4

(d) 1

Answer► (c) 4

6. If two roots of the equation x3 – px2 + qx – r = 0 are equal in magnitude but opposite in sign, then

(a) pr = q

(b) qr = p

(c) pq = r

(d) None of these

Answer► (c) pq = r

7. The equation πx = –2x2 + 6x – 9 has

(a) No solution

(b) One solution

(c) Two solutions

(d) Infinite solutions

Answer► (a) No solution

8. Two real numbers a & b are such that a + b = 3 & |a – b| = 4, then a & b are the roots of the quadratic equation

(a) 4x2 – 12x – 7 = 0

(b) 4x2 – 12x + 7 = 0

(c) 4x2 – 12x + 25 = 0 

(d) None of these

Answer► (a) 4x2 – 12x – 7 = 0

9. The values of k, for which the equation x2 + 2(k – 1) x + k + 5 = 0 possess at least one positive root, are

(a) [4, ∞) 

(b) (∞, – 1] ∪ [4, ∞)

(c) [–1, 4] 

(d) (–∞, – 1]

Answer► (d) (–∞, – 1]

10. If α (≠ 1) is a fifth root of unity and b (≠ 1) is a fourth root of unity, then z = (1 + α) (1 + β) (1 + α2) (1 + β2) (1 + α3) (1 + β3) equals

(a) α

(b) β

(c) αβ

(d) 0

Answer► (d) 0

11. The value of   is

(a) 2i

(b) –2i

(c) 2

(d) 1

Answer► (a) 2i

12. If | z – 3i| = 3, (where i = √-1) and arg z ∈ (0, π/2), then cot (arg (z)) -6/z is equal to 

(a) 0

(b) –i

(c) i

(d) π

Answer► (c) i

13. Let a, b and c are real numbers such that 4a + 2b + c = 0 and ab > 0. Then the equation ax2 + bx + c = 0 has

(a) Real roots

(b) Imaginary roots 

(c) Exactly one root 

(d) None of these

Answer► (a) Real roots

14. If both the roots of the quadratic equation x2 – 2kx + k2 + k – 5 = 0 are less than 5, then k lies in the interval

(a) [4, 5]

(b) (– ∞, 4)

(c) (6, ∞)

(d) (5, 6]

Answer► (b) (– ∞, 4)

15. For all complex numbers z1 ,z2 satisfying |z1| = 12 and |z2 – 3 – 4i| = 5 , the minimum value of  |z1 -z2| is 

(a) 0

(b) 7

(c) 2

(d) 17

Answer► (c) 2

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NCERT MCQ CLASS-11 CHAPTER-4 | MATH NCERT MCQ | PRINCIPLE OF MATHEMATICAL INDUCTION | EDUGROWN

In This Post we are  providing Chapter-4 Principle of Mathematical Induction NCERT MCQ for Class 11 Math which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON PRINCIPLE OF MATHEMATICAL INDUCTION

Principle of Mathematical Induction Class 11 MCQs Questions with Answers

Question 1.
The sum of the series 1³ + 2³ + 3³ + ………..n³ is

(a) {(n + 1)/2}²
(b) {n/2}²
(c) n(n + 1)/2
(d) {n(n + 1)/2}²

Answer: (d) {n(n + 1)/2}²

Question 2.
If n is an odd positive integer, then an + bn is divisible by :

(a) a² + b²
(b) a + b
(c) a – b
(d) none of these

Answer: (b) a + b

Question 3.
1/(1 ∙ 2) + 1/(2 ∙ 3) + 1/(3 ∙ 4) + ….. + 1/{n(n + 1)}

(a) n(n + 1)
(b) n/(n + 1)
(c) 2n/(n + 1)
(d) 3n/(n + 1)

Answer: (b) n/(n + 1)

Question 4.
The sum of the series 1² + 2² + 3² + ………..n² is

(a) n(n + 1)(2n + 1)
(b) n(n + 1)(2n + 1)/2
(c) n(n + 1)(2n + 1)/3
(d) n(n + 1)(2n + 1)/6

Answer: (d) n(n + 1)(2n + 1)/6

Question 5.
{1 – (1/2)}{1 – (1/3)}{1 – (1/4)} ……. {1 – 1/(n + 1)} =

(a) 1/(n + 1) for all n ∈ N.
(b) 1/(n + 1) for all n ∈ R
(c) n/(n + 1) for all n ∈ N.
(d) n/(n + 1) for all n ∈ R

Answer: (a) 1/(n + 1) for all n ∈ N.

Question 6.
For any natural number n, 7n – 2n is divisible by

(a) 3
(b) 4
(c) 5
(d) 7

Answer: (c) 5

Question 7.
1/(1 ∙ 2 ∙ 3) + 1/(2 ∙ 3 ∙ 4) + …….. + 1/{n(n + 1)(n + 2)} =

(a) {n(n + 3)}/{4(n + 1)(n + 2)}
(b) (n + 3)/{4(n + 1)(n + 2)}
(c) n/{4(n + 1)(n + 2)}
(d) None of these

Answer: (a) {n(n + 3)}/{4(n + 1)(n + 2)}
.

Question 8.
The nth terms of the series 3 + 7 + 13 + 21 +………. is

(a) 4n – 1
(b) n² + n + 1
(c) none of these
(d) n + 2

Answer: (b) n² + n + 1

Question 9.
n(n + 1)(n + 5) is a multiple of ____ for all n ∈ N

(a) 2
(b) 3
(c) 5
(d) 7

Answer: (b) 3.

Question 10.
Find the number of shots arranged in a complete pyramid the base of which is an equilateral triangle, each side containing n shots.

(a) n(n+1)(n+2)/3
(b) n(n+1)(n+2)/6
(c) n(n+2)/6
(d) (n+1)(n+2)/6

Answer: (b) n(n+1)(n+2)/6

Question 11.
For any natural number n, 7n – 2n is divisible by

(a) 3
(b) 4
(c) 5
(d) 7

Answer: (c) 5

Question 12.
(n² + n) is ____ for all n ∈ N.

(a) Even
(b) odd
(c) Either even or odd
(d) None of these

Answer: (a) Even

Question 13.
For all n ∈ N, 3×52n+1 + 23n+1 is divisible by

(a) 19
(b) 17
(c) 23
(d) 25

Answer: (b) 17

Question 14.
Find the number of shots arranged in a complete pyramid the base of which is an equilateral triangle, each side containing n shots.

(a) n(n+1)(n+2)/3
(b) n(n+1)(n+2)/6
(c) n(n+2)/6
(d) (n+1)(n+2)/6

Answer: (b) n(n+1)(n+2)/6

Question 15.
{1 – (1/2)}{1 – (1/3)}{1 – (1/4)} ……. {1 – 1/(n + 1)} =

(a) 1/(n + 1) for all n ∈ N.
(b) 1/(n + 1) for all n ∈ R
(c) n/(n + 1) for all n ∈ N.
(d) n/(n + 1) for all n ∈ R

Answer: (a) 1/(n + 1) for all n ∈ N.


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NCERT MCQ CLASS-11 CHAPTER-3 | MATH NCERT MCQ | TRIGONOMETRIC FUNCTIONS | EDUGROWN

In This Post we are  providing Chapter-3 Trigonometric Function NCERT MCQ for Class 11 Math  which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON TRIGONOMETRIC FUNCTION

1. If tan x = tan α , then the general solution of the equation is

(a) nπ – α

(b) 2nπ- α

(c) nπ + α

(d) 2nπ + α

Answer► (c) nπ + α

2. If cos a + 2cos b + cos c = 2 then a, b, c are in

(a) 2b = a + c

(b) b2 = a × c

(c) a = b = c

(d) None of these

Answer► (a) 2b = a + c

3. In a triangle ABC, medians AD and BE are drawn. If AD = 4, ∠DAB = π/6 and ∠ABE =π/3, then the area of the ΔABC is

(a) 8/3

(b) 16/3

(c) 32/3√3

(d) 64/3

Answer► (c) 32/3√3

4. What is the value of tan 3θ ? if tan θ = 1/2

(a) 1/5

(b) -11/2

(c) -1/5

(d) 11/2

Answer► (d) 11/2

5. The solution set of inequality 

(a) 

(b) 

(c) 

(d) 

► (d) 

6. If the median AD of a triangle ABC divides the angle ∠BAC in the ratio 1 : 2, then sinB/sinC is equal to

(a) 2 cos (A/3)

(b) (1/2) sec (A/3)

(c) (1/2) sin (A/3)

(d) 2 cosec (A/3)

Answer► (b) (1/2) sec (A/3)

7. The general solution of sin = 0 is

(a) nπ where n is a real number

(b) nπ, where n is an integer

(c) 2π

(d) π

Answer► (b) nπ, where n is an integer

8. If cos A = sin/2sinC, then ΔABC is

(a) Equilateral

(b) Isosceles

(c) Right angled

(d) None of these

Answer► (b) Isosceles

9. The solutions of the equation 4 cos2 x + 6 sin2 x = 5 are 

(a) 

(b) 

(c) 

(d) 

Answer► (a) 

10. The sum of the radii of inscribed and circumscribed circle for an n sided regular polygon of side a, is

(a) a cot (π/n) 

(b) a/2 cot(π/2n)

(c) a cot (π/2n)

(d) a/4 cot(π/2n)

Answer► (b) a/2 cot(π/2n)

11. The number of values of x in the interval [0, 3π] satisfying the equation 2 sin2 x + 5 sin x – 3 = 0 is 

(a) 6

(b) 1

(c) 2

(d) 4 

Answer► (d) 4 

12. tan(π + x)=

(a) -tan x

(b) tan π + tan x

(c) 0

(d) tan x

Answer► (d) tan x

13. The vertices angle of a triangle is divided into two parts, such that the tangent of one part is 3 times the tangent of the other and the difference of these parts is 30º, then the triangle is

(a) Isosceles 

(b) Right angled 

(c) Obtuse angled

(d) None of these

Answer► (b) Right angled 

14. The number of solutions for the equation sin 2x + cos 4x = 2 is

(a) 0

(b) 1

(c) 2

(d) ∞

Answer► (a) 0

15. The number of pairs (x, y) satisfying the equations sin x + sin y = sin (x + y) and |x| + |y| = 1 is

(a) 0

(b) 2

(c) 4

(d) 6 

Answer► (d) 6 

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NCERT MCQ CLASS-11 CHAPTER-2 | MATH NCERT MCQ | RELATIONS AND FUNCTIONS | EDUGROWN

In This Post we are  providing Chapter-2 Relations and Functions NCERT MCQ for Class 11 Math  which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON RELATIONS AND FUNCTIONS

1. The domain of the function f = {(1, 3), (3, 5), (2, 6)} is 

(a) 1, 3 and 2(b) {1, 3, 2}(c) {3, 5, 6}(d) 3, 5 and 6

Answer► (b) {1, 3, 2}


2. If n(A) = p and n(B) = q, then how many relations are there from A to B?

(a) pq(b) 3pq(c) 2pq(d) (pq)2

Answer► (c) 2pq

3. In the set W of whole numbers an equivalence relation R defined as follow : aRb iff both a and b leave same remainder when divided by 5. The equivalence class of 1 is given by

(a) {1, 6, 11, 16, ….}(b) [0, 5, 10, 15,…}(c) {2, 7, 12, 17…}(d) {4, 9, 14, 19, …}

Answer► (a) {1, 6, 11, 16, ….}


4. The point on the curve y = x2 which is nearest to (3, 0) is

(a) (1, -1)(b) (-1,1)(c) (-1,-1)(d) (1,1)

Answer► (d) (1,1)


5. If f(x) is an odd differentiable function on R, then df(x)/dx is a/an

(a) Even function(b) Odd function(c) Either even or odd function(d) Neither even nor odd function

Answer► (a) Even function


6. Let S = {1, 2, 3}. The function f : S → S defined as below have inverse for

 (a) f = {(1, 2), (2, 2), (3, 3)}(b) f = {(1, 2), (2, 1), (3, 1)}(c) f = {(1, 3), (3, 2), (2, 1)}(d) f = {(1, 3), (2, 3), (2, 1)}

Answer► (c) f = {(1, 3), (3, 2), (2, 1)}


7. The function f(x) = x – [x] has period of

(a) 0(b) 1(c) 2(d) 3

Answer► (b) 1

8. If f (0) = 0, f (1) = 1, f (2) = 2 and f (x) = f (x – 2) + f (x – 3) for x = 3, 4, 5,&.., then f(9) =

 (a) 12(b) 13(c) 14(d) 10

Answer► (d) 10


9. Let f (x) = x2 and g (x) = √x, then

(a) (fog) (2) = 4(b) (gof) (- 2) = 2(c) (gof) (2) = 4(d) (fog) (3) = 6

Answer► (b) (gof) (- 2) = 2


10. If A = [a, b], B = [c,d], C = [d, e] then {(a, c), (a, d), (a,e), (b,c), (b, d), (b, e)} is equal to

(a) A∪(B∩C)(b) A∩(B∪C)(c) A×(B∩C)(d) A×(B∪C)

Answer► (d) A×(B∪C)r


11. If f(x) = x2 and g(x) = x are two functions from R to R then f(g(2)) is

(a) 4(b) 8(c) 1(d) 2

Answer► (b) 8

12. The number of binary operations on the set {a, b} are

(a) 2(b) 4(c) 8(d) 16

Answer► (d) 16


13. If f (x) is a function such that f (x + y) = f (x) f (y) and f (3) = 125 then f (x) =

(a) 5(b) x5(c) 5x(d) 5x

Answer► (c) 5x

14. The function f : C → C defined by f (x) = ax + b/cx + d for x ∈ C where bd ≠ 0 reduces to a constant function if

(a) a = c(b) b = d(c) ad = bc(d) ab = cd

Answer► (c) ad = bc


15. If A = {1, 2, 3}, and B = {3, 6} then the number of relations from A to B is

(a) 32(b) 23(c) 2 x 3(d) 26

Answer► (d) 26

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NCERT MCQ CLASS-11 CHAPTER-1 | MATH NCERT MCQ | SETS| EDUGROWN

In This Post we are  providing Chapter-1 Sets NCERT MCQ for Class 11 Math which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON SETS

Question 1. If A = {1, 2, 3, 4, 5}, then the number of proper subsets of A is :
(a) 31
(b) 38
(c) 48
(d) 54

Answer : A

Question 2. The cardinality of the set P(P(P(f))) is
(a) 0
(b) 1
(c) 2
(d) 4
[P(A) represents power set of the set A]

Answer : D

Question 3. Let P be a set of squares, Q be set of parallelograms, R be a set of quadrilaterals and S be a set of rectangles. Consider the following :
1. P Ì Q
2. R Ì P
3. P Ì S
4. SÌ R
Which of the above are correct?
(a) 1, 2 and 3
(b) 1, 3 and 4
(c) 1, 2 and 4
(d) 3 and 4

Answer : B

Question 4. If A and B are finite sets, then which one of the following is the correct equation?
(a) n (A – B) = n (A) – n (B)
(b) n (A – B) = n (B – A)
(c) n (A – B) = n (A) – n (A ∩ B)
(d) n (A – B) = n (B) – n (A ∩ B)
[n (A) denotes the number of elements in A]

Answer : C

Question 5. If A = {x, y} then the power set of A is :
(a) {xx, yy}
(b) {f, x, y}
(c) {f,{x},{2y}}
(d) {f,{x},{y},{x,y}}

Answer : D

Question 6. Consider the following equations :
1. A – B = A – (A ∩ B)
2. A = (A ∩ B) ∪ (A – B)
3. A – (B ∪ C) = (A – B) ∪ (A – C)
Which of these is/are correct ?
(a) 1 and 3
(b) 2 only
(c) 2 and 3
(d) 1 and 2

Answer : D

Question 7. If A∪B ¹ f, then n(A∪B) = ?
(a) n(A) + n(B) – n(A∩B)
(b) n(A) – n(B) + n(A∩B)
(c) n(A) – n(B) – n(A∩ B)
(d) n(A) + n(B) + n(A∩ B)

Answer : A

Question 8. Let V = {a, e, i, o, u} and B = {a, i, k, u}. Value of V – B and B – V are respectively
(a) {e, 0} and {k}
(b) {e} and {k}
(c) {0} and {k}
(d) {e, 0} and {k, i}

Answer : A

Question 9. If A = {1, 2, 3, 4}, B = {2, 3, 5, 6} and C = {3, 4, 6,7}, then
(a) A – (B ∩ C) = {1, 3, 4}
(b) A – (B ∩ C) = {1, 2, 4}
(c) A – (B ∪ C) = {2, 3}
(d) A – (B ∪ C) = {f}

Answer : B

Question 10. If A and B are two sets, then A ∩ (A ∪ B)’ equals :
(a) A
(b) B
(c) f
(d) None

Answer : C

Question 11. How many elements has P(A), if A = f ?
(a) two
(b) one
(c) three
(d) zero

Answer : B

Question 12. Let A = {a, b}, B = {a, b, c}. What is A∪B ?
(a) {a, b}
(b) {a, c}
(c) {a, b, c}
(d) {b, c}

Answer : C

Question 13. Which of the following is correct?
(a) A∪B¹A∪A’
(b) (A∩B)’ = A’∪B’
(c) (A’ ∪B’) ¹A’∪A
(d) (A∩B)’ = A’∩B’

Answer : D

Question 14. What is the simplified representation of

(A´ ∩ B´∩C) ∪ (B∩C) ∪ (A ∩ C), where A,B, C are subsets of a set X?
(a) A
(b) B
(c) C
(d) X∩ ( A∪ B∪ C)

Answer : C

Question 15. What does the shaded portion of the Venn diagram given above represent?

(a) (P∩Q)∩(P∩R)
(b) ((P∩Q) – R)∪((P∩R) -Q)
(c) ((P∪Q) -R)∩((P∩R) -Q)
(d) ((P∩Q)∪R)∩((P∪Q) -R)

Answer : B 

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