Demorgan's Law

Q. In a survey of 100 persons, it was found that 28 read magazine A, 30 read , magazine 142 read magazine C, 8 read magazine A and B, 10 read magazine A and C, 5 read magazine B and C and 3 read all the three magazines. Find how many persons read magazine C only .

Q.

In a survey of 300 android mobile users, who make video calls, 75 people said they use only Viber, 45 use only Skype and 90 people use both. The number of persons who use neither Viber nor skype is __.

Q. Out of 300 people, 75 people use only Viber and 45 people use only Skype. 90 people use both Skype and Viber.
people use neither Viber nor Skype.

1. 225
2. 255
3. 90
4. 180

Q. Out of 200 people, 50 don't play NFS, 40 don't play dota and 10 people play no game.
people do not play both NFS and dota.

1. 100
2. 80
3. 110
4. 10

Q.

If the number of elements in each of universal set, set A and set B are represented as n(U), n(A), n(B) respectively, then the number of elements that are not in set A and not in set B is given by ___.

1. $n\left(U\right)-n(A\cap B)$

2. $n\left(AU{B}^{\prime }\right)$

3. $n\left(\right(A\cap B{)}^{\prime })$

4. $n\left(U\right)-n(A\cup B)$

Q.

In a survey of 200 students from 7 different schools, 50 people do not play NFS, 40 people do not play Dota and 10 people do not play any online game. Find the number of people who do not play both the games.

1. 80

2. 70

3. 50

4. 60

Q.

In a random survey 250 people participated. Out of 250 people who took part in the survey, 40 people have listened to Pink Floyd. 30 people have listened to metallica and 20 people have listened to John Denver. If 10 people have listened to all three then find the no. of people who have listened only Pink Floyd.

1. 25

2. 10

3. 20

4. 30

Q.

Let ∪ = {x: x is a natural number and x ≤ 10}

A = {a: a is an even natural number and a < 10}

B = {b: b is a prime number and b ≤ 9}

Then A^I ∩ B^I is

1. {2, 4, 6, 8}

2. { 3, 5, 7}

3. {1, 9, 10}

4. {2, 3, 5, 7}