Question

a merchant has coffee worth $5 a pound that she wishes to mix with 50 pounds of coffee worth $9 a pound to get a mixture worth $6 a pound. how many pounds of the $5 coffee be used?

Answer 1

Haven't seen these ones in forever, I think this is how you do it.

Let x be the pounds of $5 coffee used.

So using the equation, total price/total pounds=price per pound

(5x+50*9)/(x+50)=6

Solving for x, you get 150