Question

A jar contains 39 marbles of which 7 is blue and 22 are red and the rest are green what is the ratio of blue marbles to green marbles?

Answer 1

10 of them are green b/c 39-7-22=10
There are 10 green marbles.
It is given that there are 7 blue marbles.
So the ratio of blue marbles to green marbles is 7:10

7:10, 7/10 (they mean the same thing)