Find the common factors of:

(i) 20 and 28

(ii) 35 and 50

(iii) 56 and 120

(i) The factors of 20 are 1, 2, 4, 5, 10 and 20.

The factors of 28 are 1, 2, 4, 7, 14 and 28.

Hence, the common factors of 20 and 28 are 1, 2 and 4.

(ii) The factors of 35 are 1, 5, 7 and 35.

The factors of 50 are 1, 2, 5, 10, 25 and 50.

Hence, the common factors of 35 and 50 are 1 and 5.

(iii) The factors of 56 are 1, 2, 4, 7, 8, 14, 28 and 56.

The factors of 120 are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60 and 120.

Hence, the common factors of 56 and 120 are 1, 2, 4 and 8.