Two liters of a 30% acid solution are mixed with three liters of a 20% acid solution and five liters of a 10% acid. What percent of the mixture is acid?
.30 * 2 = .6 liter is acid
.20 * 3 = .6 liter is acid
.10 * 5 = .5 liter is acid
% total acid = ( .6 + . 6 + .5 ] ( 2 + 3 + 5) = 1.7 / 10 = 17 /100 = 17%
