Question

What are the greatest common factor of 21 30

Answer 1

factors of 21: 3,7 
factors of 30: 2, 3, 5, 6 10, 15

3 is the largest number that could be divided into the integers 

GCF is $\boxed{3}$

Answer 2

The GCF of 21 is 7 the GCF of 30 is 6. 7X3=21 5X6=30 there are no larger numbers that will go into either 21 or 30