Just the number 1.
They all have four factors.
The common factors of 35 and 45 are: 1 and 5
The factors for 25 are 1,5, and 25 The factors for 35 are 1,5, and 35 The common factors for 25 and 35 are 1, and 5
The common factors for 35 would depend upon the other number(s) with which the 35 has factors in common, but they would be drawn from the factors of 35, namely: 1, 5, 7, 35.
1,5,7,35Since 35 is a factor of 70, all of its factors are common.
The common factors of 49 and 35 are: 1 and 7
The common factors of 5 and 35 are 1 and 5.
The common factors of 35 and 75 are 1,and 5.
The positive common factors of 28 and 35 are: 1 and 7.
Since 35 is a factor of 140, all of its factors are common.
Since 35 is a factor of 70, all of its factors are common.
Yes only the one and it is 1