UGC NET CSE | December 2012 | Part 3 | Question: 34

Question

The power set of AUB, where A={2, 3, 5, 7} and B={2, 5, 8, 9}is

• A. 256
• B. 64
• C. 16
• D. 4

Answer 1

Answer : B

A = {2,3,5,7}  B= {2,5,8,9}

A∪B = {2,3,5,7,8,9}

Power set going to have 2⁶ elements which is 64

Answer 2

Answer: B

A = {2, 3, 5, 7}, B = {2, 5, 8, 9} then A U B = {2, 3, 5, 7, 8, 9}
let A be any set, then the set of all subsets of A is called power set of A and it is denoted by P(A) or 2^A.

If A= {1,2,3}, then P(A) = {ɸ, {1}, {2}, {3}, [1,2}, {2,3}, {1,3}, {1,2,3}}

If Cardinality of the power set of A is n, then |P(A)|= 2^n

|A U B| = 6
|P(A U B)| = 2^6 = 64