Question

You need a 15% acid solution for a certain test, but your supplier only ships 5% solution and 17.5% solution. If you need 20 liters of 15% acid solution, how many liters of 5% and 17.5% solution do you need?

Answer 1

4 liters of 5% and 16 liters of 17.5%

Explanation:

:)

Answer 2

4 liters of 5% and 16 liters of 17.5%

Explanation:

Let quantity of 5% be x liters and of 17.5% be y liters

x+y=20 hence y=20-x

Introducing percentages

0.05x+0.175(20-x)=0.15*20

0.05x+3.5-0.175x=3

-0.125x=-0.5

`x=\frac {-0.5}{-0.125}=4`

Therefore, y=20-x=20-4=16

You need 4 liters of 5% and 16 liters of 17.5% to achieve 20 liters of 15% acid solution