If |U| = 14, A ⊆ U, and |𝒫(A)| = 64, what is the value of |𝒫(A′)|?
Answer and explanation
Correct answer: 2^8
For any finite set X, |𝒫(X)| = 2^|X|. Since |𝒫(A)| = 64 = 2^6, we obtain |A| = 6. Because A is a subset of U and |U| = 14, its complement has |A′| = 14 − 6 = 8 elements. Therefore the power set of A′ contains 2^8 subsets. Thus option C, 2^8, is correct.
Frequently asked questions
What is the correct answer to this question?
2^8
Why is this the correct answer?
For any finite set X, |𝒫(X)| = 2^|X|. Since |𝒫(A)| = 64 = 2^6, we obtain |A| = 6. Because A is a subset of U and |U| = 14, its complement has |A′| = 14 − 6 = 8 elements. Therefore the power set of A′ contains 2^8 subsets. Thus option C, 2^8, is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Power Set and Subsets.