Chapter 3.5, Problem 6E

Mixing Feed A milling company wants to mix alfalfa which contain 20% protein, and wheat $mids{,}^{38}$ which contains 15% protein, to make cattle feed.

a. If you make a mixture of 30 pounds of alfalfa and 40 pounds of wheat mids, how many pounds of protein are in the mixture (Hint: In the 30 pounds of alfalfa, there are $30\times 0.2=6$ pounds of protein.)

b. Write a formula that gives the amount of protein in a mixture of a pounds of alfalfa and w pounds of wheat mids.

c. Suppose the milling company wants to make 1000 pounds of cattle feed that contains 17% protein. How many pounds of alfalfa and how many pounds of wheat mids must be used?