Joey has a sack of 56 marbles. There are three colors of marbles on the sack: red, yellow, and blue. If he has half as many red as blue marbles and eight more yellow than red marbles, how many of each color does he have in the sack?

Let r = # of red marblesLet 2r = # of blue marbles ... (1/2 as many red as blue, means blue is twice the red) Let r+8 = # of yellow marbles ... (8 more than the red) Total is 56 ... our equation is r + 2r + r + 8 = 56 4r + 8 = 56 4r = 56 - 8 4r = 48 r = 12 There are 12 red marbles. There are 24 blue marbles. There are 20 yellow marbles.