Question

Two even numbers have a common factor of 3

Answer 1

42 has 2, 3 and 7, and 63has 3, 3 and 7. They have 3 and 7 incommon. To find the highest common factor, multiply all of the commonprime factors together. In this case, 3 × 7 = 21, so 21 is the greatest common factor of 42 and 63