Which of the following is

**NOT**a factor of 90?Which of the following is **NOT** a factor of 90?

Detailed Explanation

A factor of a number divides evenly into that number without leaving a remainder.

Let's test each option:

15 ÷ 90 = 6 (No remainder, therefore 15 is a factor)

5 ÷ 90 = 18 (No remainder, therefore 5 is a factor)

6 ÷ 90 = 15 (No remainder, therefore 6 is a factor)

12 ÷ 90 = 7.5 (Leaves a remainder of 0.5, therefore 12 is not a factor)

Therefore, the only option that doesn't divide evenly into 90 is 12.

Let's test each option:

15 ÷ 90 = 6 (No remainder, therefore 15 is a factor)

5 ÷ 90 = 18 (No remainder, therefore 5 is a factor)

6 ÷ 90 = 15 (No remainder, therefore 6 is a factor)

12 ÷ 90 = 7.5 (Leaves a remainder of 0.5, therefore 12 is not a factor)

Therefore, the only option that doesn't divide evenly into 90 is 12.