Question

Which is a factor of 21?
4
3
6
5

Answer 1

Answer: 3

Explanation:

3 is the only number you can multiply to get 21. Example 3x7=21

Answer 2

3

Explanation:

Using listing:

`1 * 21 = 21`

`3 * 7 = 21`

No other factors are possible.

Hence, 1, 3, 7 and 21 are factors of 21.