Question

Grant plans to evaporate enough water from 22 gallons of a 16% ammonia solution to make a 24% ammonia solution. Which equation can he use to find n, the number of gallons of water he should remove?

Answer 1

Find something that doesn't change and hold on to it! Don't let it go.

In this case, the water changes, the concentration changes, the ammonia is the same.

22 gallons of 16% ==> 22 * 0.16 = 3.52 gallons ammonia

W gallons of 24% ==? W * 0.24 = 3.52 gallons ammonia