You drive a car that runs on ethanol and gas. You have a 20-gallon tank to fill and you can buy fuel that it 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?

6 answers

Can someone please help me?!?! This is solving for x & y. And it so complicated to me.! And worst of all I have a test on it tomorrow.! D:<
Let x=no. of gallons of 25% ethanol
then 20-x=number of gallons of 85%.
x*0.25 + (20-x)*0.85 = 20*0.5
Solve for x to get 35/3 gal. of 25% ethanol.
Thank you very much.(:
You're welcome!
t7u7i
How did you figure out the value of x to = 35/3 (11.6666) gal of 25% ethanol??