A 6% alcohol solution is to be mixed with a 3% alcohol solution to make 20 liters of a 4.5% alcohol solution. If x represents the number of liters of 6% alcohol solution, which of the following equations would find the number of liters of 6% alcohol solution?
A) $0.06 x + 0.03 ( 20 - x ) = 0.045 ( 20 )$
B) $0.06 x + 0.03 ( x - 20 ) = 0.045 ( 20 )$
C) $0.06 x + 0.03 ( x - 20 ) = 0.045$
D) $0.06 x + 0.03 ( x + 20 ) = 0.045$

Question

Quizplus · Accepted Answer

The equation represents the amount of alcohol in the final mixture, where the amount of alcohol in the 6% solution (0.06x) is added to the amount of alcohol in the 3% solution (0.03(20-x)). This is set equal to the amount of alcohol in the final mixture (0.045(20)). Solving for x gives the number of liters of the 6% solution needed to make the mixture. Choice B has the wrong sign in front of the 20-x term, Choice C doesn't have the (20) on the right-hand side, and Choice D has the wrong sign in front of the 20 term.

A 6% Alcohol Solution Is to Be Mixed with a 3