Question

greates common factor of 10,40

Answer 1

40: 2,2,2,5
10: 2,5
       2        5
2*5=10
GCF is 10

Answer 2

The Greatest Common Factor (GCF) of 10 and 40 is : 2 and 5. Why? because both of these numbers fit evenly into 10 and 40.

I hope this's useful/helpful ! :)