first three common factors of 3,4,5
24, 48, 72
The common factors are: 1, 2, 3, 4, 6, 12
9 and 21 only have two common factors: 1 and 3.
The only common factor is 1.
1, 2 and 5
Eight factors.
There are only 2, and these are 1 and 2.
114, 228, 342
The first three multiples of 9 are 9, 18 and 27. For them to be common, they need to be compared to another set of factors.
16 and 21 only have one common factor, the number one.
Four has three factors: 1, 2 and 4