Question

A pharmacist needs 16 liters of a 4% saline solution. He has a 1% solution and a 5% solution available. How many liters of

the 1% solution and how many liters of the 5% solution should he mix to make the 4% solution?

Answer 1

x = liters of 1% solution
y = liters of 5% solution
x + y = 16
0.01x + 0.05y = 0.04*16 = 0.64
y = 16 - x
0.01x + 0.05(16 - x) = 0.64
0.01x + 0.8 - 0.05x = 0.64
0.16 = 0.04x
x = 4
y = 12