If A = {a, b, c, d, e}, how many proper subsets of A do not contain a?
Answer and explanation
Correct answer: 16
Any subset that does not contain a can use only the remaining four elements b, c, d, and e. Each of these four elements may either be included or excluded, so the number of such subsets is 2^4 = 16. None of them can equal A because A contains a, so every one of these 16 subsets is proper. Therefore option C is correct.
Frequently asked questions
What is the correct answer to this question?
16
Why is this the correct answer?
Any subset that does not contain a can use only the remaining four elements b, c, d, and e. Each of these four elements may either be included or excluded, so the number of such subsets is 2^4 = 16. None of them can equal A because A contains a, so every one of these 16 subsets is proper. Therefore option C is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Power Set and Subsets.