math
posted by Anonymous .
sally has a bag with red,blue, and green marbles. She has twice as many blue marbles as red marbles. She has 5 times as many green marbles as red marbles. Altogether she has 24 marbles. How many of each color marble does she have? Explain how you found your answer.

r+b+g=24
g = 5r
b = 2r
r+2r+5r = 24
8r = 24
r=3
so, 3 red, 6 blue, 15 green