Question

A store mixes Kentucky bluegrass worth $12 per pound and chewing fescue worth $16 per pound. The mixture is to sell for $15 per pound. Find out how much of each should be used to make for 372 pound mixture

Answer 1

Let the amount of Kentucky Bluegrass be k.
Let the amount of Chewing Fescue be c.
$12k+16c=15\times372$
k+c=372
c=372 - k
12k + 16(372 - k) = 15 * 372 = 5580
12k + 5952 - 16k = 5580
-4k = -372
k = 93 pounds
c = 372 - 93 = 279 pounds