Question

The ratio of blue marbles to white marbles in a bag is 4 to 5 at this rate how many blue marbles are there if there are 15 white marbles

Answer 1

the answer is 12 blue marbles

Answer 2

Sum up 4 and 5; result of that is 9. Then 4/9 of the marbles in the bag are blue and 5/9 are white.

One of the easier ways in which you could solve this problem would be to write and solve an equation of ratios:

blue 4 x
------- = ------ = -------
white 5 15

5x = 60, and thus x = 12. There are 12 blue marbles.

Note that 12/15= 4/5 or 4:5.