Question 27934
Let x = the required number of pounds of 16%-protein soybean meal
15-x = the required number of pounds of 10%-protein corn meal.
You want x lbs of 16%-protein (0.16x) plus (15-x) lbs of 0.10%-protein (0.10(15-x)) to equal 15 lbs of 12% (0.12)(15) of mixture.
Change the percents to their eqivalent decimals and write the equation.

{{{0.16x + 0.10(15-x) = 0.12(15)}}} Simplify and solve for x.
{{{0.16x + 1.5 - 0.1x = 1.8}}} Combine the x-terms.
{{{0.06x + 1.5 = 1.8}}} Subtract 1.5 from both sides of the equation.
{{{0.06x = 0.3}}} Divide both sides by 0.06
{{{x = 5}}}

You will need 5 lbs of 16%-protein soybean meal and 10 lbs of 10%-protein corn meal to make a 15-lb mixture that is 12% protein.