Question

50 POINTS!!!!! HELP Soybean meal is 16% protein; cornmeal is 8% protein.How many pounds of each should be mixed together in order to get 320-lb mixture that is 9% protein?
How many pounds of cornmeal should be in the mixture? How many pounds of soybean should be in the mixture?

Answer 1

The first thing we are going to do for this case is define variables.
 We have then:
 x: Amount of soybean meal
 320 - x: quantity of cornmeal
 We now write the equation that models the problem:
 $0.16x + 0.08 (320-x) = 0.09 (320)$
 Rewriting we have:
 $0.16x + 25.6 - 0.08x = 28.8$
 From here, we clear x:
 $0.16x - 0.08x = 28.8 - 25.6 0.08x = 3.2 x = 3.2 / 0.08 x = 40$
 Then, the amount of Soybean meal is:
 $x = 40 lb$
 The amount of cornmeal is:
 $320 - x = 320 - 40 = 280 lb$
 Answer:
 cornmeal: 280 lb
 Soybean: 40 lb.