Question

Express the given sets in roster form:

(vii) C = {All composite numbers between 2 and 20}.

Answer 1

Step: Expressing set C in roster form

We know that, the numbers which are divisible by another number other than 1 and itself are called composite numbers.

Given, C = {All composite numbers between 2 and 20}.

Composite numbers between 2 and 20 are 4, 6, 8, 9, 10, 12, 14, 15, 16 and 18.

Hence, the roster form of set is
C = {4, 6, 8, 9, 10, 12, 14, 15, 16, 18}.