Determine GCF(40,100)
GCF = Largest factor that divides numbers
1,2,4,5,8,10,20,40
1,2,4,5,10,20,25
1,2,4,5,10,20
GCF(40,100) = 20
Since GCF ≠ 1, they are not relatively prime (co-prime)
Since GCF ≠ 1 and have a difference of two, the numbers are not twin prime