What is the GCF that two numbers between 40 and50 can have.

The greatest common factor is the biggest counting number (1,2,3,4,5,6 ... and not. 234 or 3/4) that is a factor of both numbers so

40=2*2*2*5

50=2*5*5

the numbers 2 and 5 are in both so the greatest common factor is 2*5=10

10 is the greastest common factor