What are the possible factors of 

(a) 12

(b) 18?

(a) Possible factors of 12 are:

12 = 1 × 12; 12 = 2 × 6; 12 = 3 × 4

Hence, the factors of 12 are 1, 2, 3, 4, 6 and 12.

(b) Possible factors of 18 are:

18 = 1 × 18; 18 = 2 × 9; 18 = 3 × 6

Hence, the factors of 18 are 1, 2, 3, 6, 9 and 18.