Question

Which one of the following is the correct representation of set A = {2,4,8,16….} in set builder form?

(a) {x: x = 2n where n ∈ N}

(b) {x: x = 2^n where n ∈ N}

(c) {x: x = 4n where n ∈ N}

(d) {x: x = 2n+4 where n ∈ N}

I have been asked this question in final exam.

Question is taken from Sets and their Representations in section Sets of Mathematics – Class 11

Answer 1

The correct answer is (b) {x: x = 2^n where n ∈ N}

For explanation: The sequence is a geometric progression with base 2 hence 2^n is the correct answer.