Question

A merchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. How many pounds of the &60 coffee should be used?

Answer 1

100 lbs

Explanation:

Let x represent the number pounds of $60 coffee that should be used to create the mix. The total cost of the mix will be ...

60x + 90·50 = 70(x+50)

60x +4500 = 70x +3500 . . . . simplify

1000 = 10x . . . . . . . . . . . . . . . . subtract 3500+60x

100 = x . . . . . . . . . . . . . . . . . . . divide by 10

The merchant should use 100 pounds of the $60 coffee.

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The cost of the mix parts and the total mix is figured from ...

(dollars/lb)×(lbs) = dollars