Question

The greatest common factor of 42 & 15

Answer 1

42 : 2 = 21

21 : 3 = 7

7 : 7 = 1

42 = 2 · 3 · 7

15 : 3 = 5

5 : 5 = 1

15 = 3 · 5

GCF(42, 15) = 3