If A = {1, 2, 3, 4, 5}, how many one-element subsets are there in P(A)?
Answer and explanation
Correct answer: 5
A one-element subset, also called a singleton, is formed by choosing exactly one element from A. Since A contains five distinct elements, its singleton subsets are {1}, {2}, {3}, {4}, and {5}. Thus P(A) contains exactly five one-element subsets. The number 10 would count two-element subsets, because C(5, 2) = 10, not singleton subsets.
Frequently asked questions
What is the correct answer to this question?
5
Why is this the correct answer?
A one-element subset, also called a singleton, is formed by choosing exactly one element from A. Since A contains five distinct elements, its singleton subsets are {1}, {2}, {3}, {4}, and {5}. Thus P(A) contains exactly five one-element subsets. The number 10 would count two-element subsets, because C(5, 2) = 10, not singleton subsets.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Power Set and Subsets.
