The HCF of 70, 42, 28 is?

The HCF of 70, 42, 28 is?

Explanation

Factors of 70: 1, 2, 5, 7, 10, 14, 35, 70

Factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

Factors of 28: 1, 2, 4, 7, 14, 28

Common factors: 1, 2, 7, 14 → Highest is 14

So, HCF = 14.