Question

a merchant has coffee worth $60 a pound and she wants to mix with 70 pounds of coffee worth $90 a pound to get a mixture that is worth $70a pound. How many pounds of $60 coffee should be used.
A.105lb
B. 210lb
C. 70lb
D. 140lb

Answer 1

you have \(90\times 70=6300\) worth of coffee at present. if you add \(x\) amount of $60 coffee you will have \(6300+60x\) worth of coffee and a total of \(70+x\) pounds of coffee that you want to be worth $70 a pound, so set
\[6300+60x=70(70+x)\] and solve for \(x\)

Answer 2

ok working it now

Answer 3

140