How many liters of a 90% acid solution must be mixed with a 15% acid solution to get 750 L of 80% acid solution

Question

This is a mixture problem. It would be great to have an answer as soon as possible! Thanks!

Answer 1

Let x = the number of liters of the 90% acid solution

Let y = the number of liters of the 15% acid solution

x + y = 750      y = 750 - x

.90x + .15y = .80(750)     Multiply both sides of the equation by 100.

90x + 15y = 80(750) = 60,000

90x + 15(750 - x) = 60,000

90x + 11,250 - 15x = 60,000

75x = 48,750

x = 650 liters

y = 750 - 650

y = 100 liters