Problema Solution

In a chemistry class 12 L of a 12% alcohol solution must be mixed with a 20% solution to get a 14% solution. How many liters of the 20% solution are needed?

Answer provided by our tutors

Let x = liters 20% solution to be added

then

.12(12) + .20x = .14(12+x)

.12(12) + .20x = .14(12+x)

1.44 + .20x = 1.68 + .14x

.20x = .24 + .14x

.06x = .24

x = 4 liters