How many pounds of each should he use

Question

A merchant wants to mix peanuts worth $3 per pound with jelly beans worth $1.50 per pound to make 30 pounds of a mixture worth $2.10 per pound.

Answer 1

If we use x pounds of peanuts with a value of 3x

Then we add 30-x pounds of jelly beans with value of 1.5(30-x)

To sum to 30 pounds mixture worth 2.1(30)

 

3x + 1.5(30-x) = 2.1(30)

3x + 45 - 1.5x = 63

1.5x = 18

x = 12 pounds of peanuts

30-x = 18 pounds of jelly beans