Question

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 12% protein

Answer 1

Work: .14x+.07(280-x)=.12*280
.14x+19.6-.07x=33.6
.07x=33.6-19.6
.07x=14
x=14/.07

x=200 lbs of soybeans is used.
280-200=80 lbs. of cornmeal is used.
.14*200+.07*80=.12*280
28+5.6=33.6
33.6=33.6