Question

How many liters of a solution that is 15 percent salt must be added to 5 liters of a solution that is 8 percent salt so that the resulting solution is 10 percent salt?

• A. 3
• B. 5
• C. 2
• D. 4

Answer 1

Answer: (C)

2

Let n represent the number of liters of the 15 % solution. The amount of salt in the 15 % solution [0.15n] plus the amount of salt in the 8 % solution [(0.08)(5)] must be equal to the amount of salt in the 10 % mixture [0.10(n + 5)] Therefore,

$0.15n+0.08\left(5\right)=0.10(n+5)$

$15n+40=10n+50$

$5n=10$

$n=2$ liters

Two liters of the 15 % salt solution must be added to the 8 % solution to obtain the 10 % solution.