Question

what is the common denominator for theses: 5/6, 7/9, 3/5
A. 59
B. 9
C. 90
I think it is 90

Answer 1

You are correct

For it to be a common denominator, It must be divisible by all the other denominators.

Out of your options, 90 is the only one that can be factorised with a 6, 9 and 5