Soybean meal is 14% protein; cornmeal is 7% protein. How many pounds of each should be mixed together in order to get 280-lb mixture that is 10% protein?

Answer 1

.14s + .07(280-s) = .10*280
.14s + 19.6 - .07s = 28
.07s = 8.4
s = 120

so, use 120 lbs of soybean and 160 lbs of corn

Answer 2

x+y=2
y-x=2