How many gallons of gasoline that is 5% ethanol must be added to 2000 gallons of gasoline with no ethanol to get a mixture that is 3% ethanol?

Question

The directions say to solve the problem. 

Answer 1

.05x = .03(2000+x)

 

x=3000 gallons

 

you get this answer by finding the same ethanol amounts on each side