Question

Find the greatest common factor of 21, 35, 49.

Answer 1

You can use formulas for finding them but this is my best method.

Explanation:

21=3×7

35=5×7

49=7×7

Finding the hcf or gcf you will first find the common numbers between all the prime factors which is 7.

Therefore gcf of 21,35 and 49 is 7