A grocer wishes to blend 2 different coffee brands. he wants to make a blend of 480 pounds to sell at $2.68 a pound. if he uses a blend of coffee worth $2.50 a pound with another blend worth $2.80 a pound, how many pounds of each does he use?

1 Answer
Sep 3, 2015

I found:
"brand"_1=192brand1=192 pounds
"brand"_2=288brand2=288 pounds

Explanation:

Call the quantities of the two blends x_1x1 and x_2x2 so you get:
{(x_1+x_2=480),(2.50x_1+2.80x_2=2.68*480):}
solving by substitution you get:
from the first equation:
x_1=480-x_2
substitute into the second equation:
2.50(480-x_2)+2.80x_2=1286.4
1200-2.50x_2+2.80x_2=1286.4
0.3x_2=86.4
x_2=288 pounds
and so:
x_1=480-288=192 pounds