The ratio of red marbles to blue marbles in a box is 2:5. What is the ratio of number of blue marbles to the total number of marbles in the box?
The correct option is A 5:7
Suppose the number of red marbles is 2x and that of blue marbles is 5x. Hence, total number of marbles will be 7x.
Now, the ratio of blue marbles to total marbles = 5:7.