15
Six.
1 + 15 + 3 + 5 = 24
The common factors are: 1, 3, 5, 15.
The common factors of 10 and 15 are: 1 and 5.
Since 5 is a factor of 15, all of its factors are common.
1,3,5 and 15,
The common factors of 6 and 15 is 1 and 3 that's all
The common factors are: 1, 5.
15
Common factors of 50, 35, and 15 are: 1 and 5.
Common factors of 15 and 75 are: 1, 3, and 5.