walnut and cashew mix

Question

how many pounds of walnuts that cost $.80/lb must be mixed with 8 lbs of cashews that cost $1.25/lb to make a mixture of nuts that cost $1.00/lb??

Answer 1

8(1.25) + x(.8) = (8+x)(1)

10 +.8x = 8 +x

x-.8x = 10-8

.2x = 2

x = 2/.2 = 10 pounds of 80 cent per pound mixed with 8 pounds of $1.25 per pound yield 18 pounds of $1 per pound mixture

.8 is within .2 of 1

1.25 is within .25 of 1

you need .25/.2 times as much 80 cents per pound as $1.25 per pound

25/20 = 5/4

10/8 = 5/4