A store sells cashews for 600 per pound and peanuts for 300

A store sells cashews for $6.00 per pound and peanuts for $3.00 per pound. The manager decides to mix 20 pounds of peanuts with soma cashews and sell the mixture for $4.00 per pound. How many pounds of cashews should be mixed with the peanuts so that the mixture will produce the same revenue as would selling the nuts separately? There should be pounds of cashews in the mixture.

Solution

let number of pounds of cashews mixed =x

revenue =number of pounds sold *price per pound

revenue for selling mixture =(20+x)*4

revnue when sold seperately =(x*6)+(20*3)

revenues are given same

(20+x)*4=(6*x)+(20*3)

80+4x=6x+60

6x-4x=80-60

2x=20

x=10

there should be 10 pounds of cashews in the mixture