A bag contains yellow, green, blue, and white marbles in the ratio 4:2:3:8 . If the bag contains 18 green marbles, then how many blue marbles are there?
4 + 2 + 3 + 8==17 sum of all ratios
18 / 2 ==9 - share of the green ratio.
9 x 3 ==27 blue marbles.
