An 80% acid solution is to be mixed with a 30% solution to get 90 gallons of a 50% solution. How many gallons of each solution are needed?

2 answers

0.8x + 0.3(90-x) = .5(90)

.8x + 27 -.3x = 45
.5x +27 = 45
.5x + 27 - 27 = 45-27

.5x = 18
x = 36

36 at 80%
54 at 30%
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