Problema Solution

Shop sells walnuts for $4 a pound and cashews for $7 a pound. How many pounds of cashews should be mixed with 10 pounds of walnuts to obtain a mixture that sells for $5.50 a pound?

Answer provided by our tutors

let


x = the weight of the cashews needed for the mix


the cost of 10 pounds of walnuts is 10*4 = $14

the cost of x pounds of cashews is x*7

the cost of (10 + x) pounds of mix will be 5.50*(10 + x)


14 + 7x = 5.50 (10 + x)


by solving this equation we find


x = 82/3


x = 27.33 pounds


27.33 pounds cashews should be used for the mix.