Question

Please help!!!

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% solution and 16 liters of 17.5% solution

Explanation:

If x is the volume of 5% solution, and y is the volume of 17.5% solution, then:

x + y = 20

0.05 x + 0.175 y = 0.15 (20)

Solve the system of equations using substitution or elimination. Using substitution:

0.05 x + 0.175 (20 − x) = 0.15 (20)

0.05 x + 3.5 − 0.175 x = 3

0.5 = 0.125 x

x = 4

y = 16

You need 4 liters of 5% solution and 16 liters of 17.5% solution.