A merchant has coffee worth $40 a pound that she wishes to mix with 60 pounds of coffee worth $90 a pound to get a mixture that can be sold for $70 a pound. How many pounds of the $40 coffee should be used?
how do i solve this
Let x = the number of pounds of cheaper coffee.
Since the merchant is mixing this with more expensive coffee, then
x + 60 = the number of pounds of medium priced mixed coffee.
The equation is gotten from this
+ =
(x)($40) + (60)($90) = (x + 60)($70) or
40x + 5400 = 70(x + 60)
Solve that equation and get x = 40
Answer: 40 pounds of $40 coffee.
Edwin