A 75% antifreeze solution is to be mixed with a 90% antifreeze solution to get 360 liters of a 85% solution.

Question

How many liters of the 75% and how many liters of the 90% solutions will be used?

Answer 1

90-85=5

85-75=10

10/5 = 2

twice as much 85% is needed as 75%

240 Liters of 90% and 120 Liters of 75% mixed yield 360 Liters of 85%

check the answers:

.9(240) + .75(120) = 216+ 90= 306 = .85(360)

.9x + .75(360-x) = .85(360)

.9x-.75x = .85(360)-.75(360)

.15x = .1(360)

x = 36/.15 = 240 Liters of 90%

360-240= 120 Liters of 75%