A dairy farmer wants to mix a 20% protein supplement and a standard 10% protein ration to make 1200 pounds of a high-grade 15% protein ration. How many pounds of each should he use?

Answer 1

If there are x lbs of the 20% protein, then the rest (1200-x) is 10%.

So, adding up the amounts of protein, it must equal the total:

.20x + .10(1200-x) = .15(1200)

Since 15% is halfway between 10% and 20%, expect the mix to be half and half.