# Set Theory and Algebra MCQ - Sets

16:

If f : R ---->R defined by f(x) = x2 + 1, then values of f -1 (17) and  f -1(-3) are respectively

 A. {Ø}, (4, - 4) B. {3,-3},{Ø} C. {Ø},{3,-3} D. {4,-4},Ø Answer Report Discuss Option: D Explanation : Click on Discuss to view users comments. Write your comments here:
17:

In a beauty contest, half the number of experts voted for Mr. A and two thirds voted for Mr. B. 10 voted for both and 6 did not vote for either. How many experts were there in all ?

 A. 18 B. 36 C. 24 D. None of these Answer Report Discuss Option: C Explanation : Click on Discuss to view users comments. Write your comments here:
18:

Let n(A) denotes the number of elements in set A. If n(A) =p and n(B) = q, then how many ordered pairs (a, b) are there with a ∈ A and b ∈ B ?

 A. p2 B. p x q C. p + q D. 2 pq Answer Report Discuss Option: B Explanation : Click on Discuss to view users comments. Write your comments here:
19:

The set of all Equivalence classes of a set A of cardinality C

 A. has the same cardinality as A B. forms a partition of A C. is of cardinality 2C D. is of cardinality C2 Answer Report Discuss Option: B Explanation : Click on Discuss to view users comments. Write your comments here:
20:

Let Z denote the set of all integers.
Define f : Z —> Z by
f(x) = {x / 2 (x is even)
0     (x is odd)
then f is

 A. onto but not one-one B. one-one but not onto C. one-one and onto D. neither one-one nor-onto Answer Report Discuss Option: A Explanation : Click on Discuss to view users comments. Write your comments here: