Professor Baird wants to mix a solution containing 10% acid with one containing 15% acid to obtain a 20 ounce solution containing 12% acid. How many ounces of the 10% solution should the professor use?

Question

Translate the word problem into an equation.

Answer 1

add up the amount of acid in each part:

.10x + .15(20-x) = .12(20)
x = 12

so, 12 oz 10% and 8 oz 15%