Question

Shanice wants to make a 72% alcojol solution. She has already poured 2L of pure water into a beaker. How many L of a 90% alcohol solution must she add to this to create the desired mixture

Answer 1

8 L

Explanation:

If x is the volume of 90% alcohol, then:

(0.90)(x) + (0)(2) = 0.72(x + 2)

0.90x = 0.72x + 1.44

0.18x = 1.44

x = 8