# The bag contained red marbles and blue marbles. If the ratio of red marbles to blue marbles was 5 to 3, what fraction of the marbles were blue?

Oct 25, 2016

$\frac{3}{8}$ of the marbles in the bag are blue.
A ratio of $5$ to $3$ means that for every $5$ red marbles, there are $3$ blue marbles. We also need a total number of marbles, so we must find the sum of red and blue marbles.
$5 + 3 = 8$
So $3$ of every $8$ marbles in the bag are blue. This means that $\frac{3}{8}$ of the marbles in the bag are blue.