Question

Find all the common factors of the numbers 6, 12 and 15.

• A. 1 and 2
• B. 2 and 3
• C. 1 and 3
• D. 1, 3 and 6

Answer 1

The correct option is C 1 and 3

6 = 1 × 6
= 2 × 3
Factors of 6: 1, 2,3 and 6

12 = 1 × 12
= 2 × 6
= 3 × 4
Factors of 12: 1, 2, 3, 4, 6 and 12

15 = 1 × 15
= 3 × 5
Factors of 15: 1, 3, 5 and 15

So, common factors are 1 and 3.