Just 1.
Since 100 is a factor of 200, all of its factors are common.
They all have factors of 1 and 5 in common
The common factors are: 1, 5, 25.
The common factors are: 1, 2, 5, 10, 25, 50.
1, 5 and 25
The common factors of 58 and 100 are: 1, 2
The common factors of 75 and 100 are 1, 5 and 25.
The common factors of 100 and 225 are: 1, 5, and 25
49 and 100 share no common factors aside from 1.
The common factors of 16 and 100 are 1, 2 and 4.
Common factors of 34 and 100 are: 1 and 2.
The common factors of 24 and 100 are 1, 2 and 4