Question

Which set contains only composite numbers? A. 21, 27, 33 B. 20, 23, 30 C. 22, 24, 29 D. 24, 27, 31

Answer 1

Answer: A

Explanation:

A composite number has more factors than 1.

The numbers 21, 27 and 33 are all composite because:

7 x 3 = 21

9 x 3 = 27

11 x 3 = 33

The answer is A.