One of Anne’s most important duties at the clinic is to prepare solutions with the correct amount of anesthetic for animals undergoing surgery. For today’s surgery, she needs 250 milliliters of a 20% solution, but only has a 10% solution and a 60% solution available.

Question

How many milliliters of the 10% solution must Anne mix with the 60% solution to obtain the required solution?

Answer 1

amount of the 10% solution ---- x ml
amount of the 60% solution ---- 250-x ml

.1x + .6(250-x) = .2(250)
times 10
x + 6(250-x) = 2(250)
x + 1500 - 6x = 500
-5x = -1000
x = 200

so 200 ml of the 10% stuff, and 50 ml of the 60% stuff