<PRE><B>Question 1164359</B>
A coffee merchant combines coffee that costs $7 per pound with coffee that costs $3.30 per pound.
 How many pounds of each should be used to make 25 lb of a blend costing $5.89 per pound?
:
let a = amt of $7 coffee required
the final amt is to be 25 lb, therefore
(25-a) = amt of $3.30 coffee required
:
A typical mixture equation
7a + 3.30(25-a) = 5.89(25)
7a + 82.5 - 3.3a = 147.25
7a - 3.3a = 147.25 - 82.50
3.7a = 64.75
a = 64.75/
a = 17.5 lb of $7 coffee
and
25 - 17.5 = 7.5 lb of $3.30 coffee
:
:
Check this out
7(17.5) + 3.3(7.5) = 5.89(25)
122.50 + 24.75 = 147.25</PRE>