Question

The set-builder representation of set $B=\{1,3,5,7,9\}$ is ______.

• A. B = {x: x is a prime number less than 10}
• B. B = {x: x is an odd number less than 10}
• C. B = {x: x is an odd natural number}
• D. B = {x: x is an odd natural number less than 10}

Answer 1

The correct option is D B = {x: x is an odd natural number less than 10}

Given that, B = {1, 3, 5, 7, 9},

Here all the elements of the set are natural numbers. Also they are all odd and less than 10.

So, B is a set of all odd natural numbers less than 10.

$\therefore$ The set builder form of the set B is

B = {x: x is an odd natural number less than 10}