EASY
Earn 100

Verify the commutative property of union of sets for the following.

A=1,2,3 and B=2,3,4,5

Important Questions on Sets

MEDIUM
In a certain town, 25% of the families own a phone and 15% own a car; 65% families own neither a phone nor a car and 2000 families own both a car and a phone. Consider the following three statements:

i 5% families own both a car and a phone.

ii 35% families own either a car or a phone.

iii 40000 families live in the town.

Then,
EASY
Let X=nN:1n50. If A=nX: n is a multiple of 2 and B=nX: n is a multiple of 7, then the number of elements in the smallest subset of X, containing both A and B, is.
MEDIUM
If A=xR:x<2 and B=xR:x-23; then
EASY
A survey shows that 73% of the persons working in an office like coffee, whereas 65% like tea. If x denotes the percentage of them, who like both coffee and tea, then x cannot be:
MEDIUM
Which of the following is not correct?
MEDIUM
A survey shows that 63% of the people in a city read newspaper A whereas 76% read news paper B. If  x% of the people read both the newspapers, then a possible value of x can be:
EASY
If A={x|xN,x is a prime number less than 12} and B={x|xNx is factor of 10}, then AB=
HARD
Let A=θR:13sinθ+23cosθ2=13sin2θ+23cos2θ. Then
EASY
Transpose of a row matrix is __________
MEDIUM
In a class of 140 students numbered 1 to140 , all even numbered students opted Mathematics course, those whose number is divisible by 3 opted Physics course and those whose number is divisible by 5 opted Chemistry course. Then the number of students who did not opt for any of the three courses is:
HARD

Let i=150Xi=i=1nYi=T, where each Xi contains 10 elements and each Yi contains 5 elements. If each element of the set T is an element of exactly 20 of sets Xi's and exactly 6 of sets Yi's then n is equal to :

HARD
In a certain town, 25% families own a phone,15% families own a car, 65% families own neither a phone nor a car and 2000 families own both a car and a phone. Consider the following Statements (S):
S1: 35% families own at least one of a car or a phone.
S2: 40,000 families live in the town.
Then:
MEDIUM
Consider the two sets:
A={mR: both the roots of x2-(m+1)x+m+4=0 are real } and B=[-3,5)
Which of the following is not true?
EASY
If AB, then AΔB is equal to
EASY
Let A and B be two sets such that AX=BX=ϕ and AX=BX for same set X. Then,
MEDIUM
Let A={nN:n is a 3-digit number} B=9k+2:kN and C=9k+l:kN for some l0<l<9. If the sum of all the elements of the set ABC is 274×400, then l is equal to
EASY
If A and B are disjoint sets, then BA', where A' is complement of A, is equal to
MEDIUM
Two newspapers A and B are published in a city. It is known that 25% of the city population reads A and 20% reads B while 8% reads both A and B. Further, 30% of those who read A but not B look into advertisements and 40% of those who read B but not A also look into advertisements, while 50% of those who read both A and B look into advertisements. Then the percentage of the population who look into advertisements is:
HARD
For any three sets A, B and C the set (ABC)AB'C''C' is equal to
HARD
In a group of 100 persons, 80 people can speak Malayalam and 60 can speak English. Then the number of people who speak English only is