I have 8 cups of a juice drink consisdting of 25% oj and 75% apple juice. I want to make a mix with 40% oj. how many cups of oj must I add?

2 answers

Oj: x
Apple juice: (8-x)
.25x + .75(8-x) = .4(8)
.25x + 6 -.75x = 3.2
6 -0.5x = 3.2
-.5x = 3.2-6
-.5x = -2.8
x = 5.6
OJ
.5(8) + x = 2+x

Total
8 + x
so
2+x = .4(8+x)

2 + x = 3.2 + .4 x

.6 x = 1.2

x = 2