SOLUTION: You drive a car that runs on ethanol and gas. You have a 20-gallon tank to fill and you can buy fuel that is either 25 percent ethanol or 85 percent ethanol. How much of each type

Algebra ->  Systems-of-equations -> SOLUTION: You drive a car that runs on ethanol and gas. You have a 20-gallon tank to fill and you can buy fuel that is either 25 percent ethanol or 85 percent ethanol. How much of each type       Log On


   

Question 962310: You drive a car that runs on ethanol and gas. You have a 20-gallon tank to fill and you can buy fuel that is either 25 percent ethanol or 85 percent ethanol. How much of each type of fuel should you buy to fill your tank so that it is 50 percent ethanol?
Step by step please
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
You drive a car that runs on ethanol and gas. You have a 20-gallon tank to fill and you can buy fuel that is either 25 percent ethanol or 85 percent ethanol. How much of each type of fuel should you buy to fill your tank so that it is 50 percent ethanol?
***
let x=amt of 25% ethanol to buy
20-x=amt of 85% ethanol to buy
..
25%x+85%(20-x)=50%*20
.25x+17-0.85x=10
0.60x=7
x=11 2/3
20-x=8 1/3
amt of 25% ethanol to buy=11 2/3 gal
amt of 85% ethanol to buy= 8 1/3 gal