Carla always sorts her M&M's before eating them. One Day she noticed that 2/5 of of them were red, 1/4 of them were brown,3/10 of them were green, and that 10 of them were yellow.

How many total M&M's?
How many were red?
How many were brown?
How many were green?

total = x

(2/5)x + (1/4)x + (3/10)x + 10 = x
times 20
8x + 5x + 6x + 200 = 20x
200 = x
x = 200

check: (2/5)200 = 80 red
(1/4)200 = 50 brown
3/10(200) = 60 green
10 yellow

80+50+60+10=200