Maths Sets - Online Test
Q1. If A⊂B , then
Answer : Option D
Explaination / Solution:
Q2. Let A = { a ,b ,c } , B = { a, b } , C = { a, b, d } , D = { c , d } and E = { d } . Then which of the following statement is not correct ?
Answer : Option C
Explaination / Solution:
Q3. A-B is equal to
Answer : Option A
Explaination / Solution:
Q4. If a set A has n elements then the total number of subsets of A is
Answer : Option C
Explaination / Solution:
The total no of subsets=2n
Q5. If A , B , C be any three sets such that A∪B=A∪C and A∩B=A∩C , then
Answer : Option C
Explaination / Solution:
Q6. Given the sets A = { 1, 2, 3 } , B = { 3 , 4 } , C = { 4 , 5, 6 } , then A ∪( B ∩ C ) is
Answer : Option C
Explaination / Solution:
Q7. Sets A and B have 3 and 6 elements respectively . What can be the minimum number of elements in A U B
Answer : Option D
Explaination / Solution:
n(A) = 3
n(B)=6
n(AUB) = n(A)+n(B)-n(AB)
for minimum number of elements in
n(AB)= 3
so n(AUB = 6
Q8. Two finite sets have m and n elements. The total number of subsets of the first set is 56 more than the total number of subsets of the second set. The values of m and n are
Answer : Option B
Explaination / Solution:
Let A and B be two sets having m and n elements respectively.Then,
Number of subsets of A=2m,Number of subsets of B=2n
It is given that 2m-2n=56
so,2n(2m-n-1)=23(23-1)
n=3 and m-n=3n=3 and m=6
Q9. The number of proper subsets of the set { 1, 2 , 3 } is :
Answer : Option B
Explaination / Solution:
The no of proper subsets=2n-1=23-1=7
Here n=no of elements of given set=3
Q10. If A , B and C are non – empty sets , then ( A – B ) ∪( B – A ) equals :
Answer : Option A
Explaination / Solution:
