Problema Solution

Soy bean meal is 14% protein;cornmeal is 7% protein. How many pounds of each should be mixed together in order to 280-lb mixture that is 11% protein? How many pounds of the cornmeal should be in the mixture? How many pounds of the soy bean meal should be in the mixture?

Answer provided by our tutors

Let x be the pounds of soy bean.

Let y be the pounds of cornmeal.

x + y = 280

Both add up to 280 pounds.

x = 280 - y 

0.14x + 0.07y = 0.11(280)

Basically 14% of soybean and 7% of cornmeal will make 11% protein in the mixture. 

Now you just plug in the x we found. 

0.14(280 - y) + 0.07y = 0.11(280)

39.2 - 0.14y + 0.07y = 30.8

- 0.07y = -8.4

y = 120

So you need 120 pounds of cornmeal and 280-120= 160 pounds of soybean.