a store mixes red fescue worth $12 per pound and chewings 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 a 552- pound mixture.


Sagot :

Answer is: 414 pounds of red fescue and 138 pounds of chewings fescue is needed to produce 552 pounds of mixture.

Explanation:
x - how much of red fescue is needed for one pound of mixture
y - how much of chewings fescue is needed for one pound of mixture
x*12+ y*16 = 15x + y = 1
so, x=1-y
putting it into first line:
(1-y)*12 + y*16 = 15
12 - 12*y + 16*y = 15
4*y = 3
y=3/4
so, x= 1-3/4; x=1/4
So to produce 552 pounds of mixture we need..To produce 1 pound of mixture we need: 3/4 pound of red fescue and 1/4 pound of chewing fescue so to produce 552 pounds of miture we need:
552*3/4 - red fescue, which is 414 pounds needed
and
552/4 - chewings fescue, which is 138 pounds needed

Answer:

e+ f = 8 (total solution)

8e + 56f = 20*8 (total saline)

---

e+ f = 8

e + 7f = 20

------------ Subtract

-6f = -12

f = 2

e = 6