Question 204888

OK, WE'LL FOLLOW THE HINT:

Let x=lbs of corn
And y=lbs of soybean meal
Now we are told that:
x+y=200-------------------------eq1
Now we know that the amount of pure crude protein before they are mixed (0.065x+0.45y) has to equal the amount of pure crude protein after they are mixed (0.15*200), so:

0.065x+0.45y=0.15*200 simplify
0.065x+0.45y=30------------------------eq2

Multiply eq1 by 0.065 (we get: 0.065x+0.065y=13) and then subtract it from eq2 and we get:
0.385y=17  divide each side by 0.385
y=44.2 lb ----------------------lbs of soybean meal needed
substitute y=44.2 into eq1:
x+44.2=200
x=200-44.2=155.8---------------lbs of corn needed

CK
0.065*155.8+0.45*44.2=0.15*200
10.1+19.9=30
30=30

Hope this helps---ptaylor