Question

a person wishes to mix coffee worth $9per pound with coffee worth $3 per pound to get a 90 lb of a mixture worth $3 per lb. how many pounds of the $9 and $3 coffees will be needed?

Answer 1

31 pounds of 3$ and 12 of the 9$

Answer 2

you need 90 pounds of the 3 dollar coffee. if you added even a single pound of 9 dollar coffee the mixture would be more than 3 dollars.