A bag contains yellow, green, blue, and white marbles. The ratio of yellow, green, blue, and white marbles is 1:2:3:4. If the bag contains 180 marbles, then how many blue marbles are there?
1 + 2 + 3 + 4==10 sum of all ratios.
180 / 10 ==18 - this is the constant
18 x 1 ==18 yellow marbles
18 x 2==36 green marbles
18 x 3==54 blue narbles
18 x 4==72 white marbles.
