A scientist has 15 barrels of gasoline with 8% ethanol content. How much pure ethanol (100% ethanol) needs to be added to the 15 barrels to create a gasoline mixture with 10% ethanol content?
The correct amount of pure ethanol to be added is
barrel(s).

At the "no mutants allowed" country farm, every sheep has 4 legs, every chicken has two legs, and all animals have only 1 head. asked to count how many sheep and chicken are in the fields, a farm boy reports back that there are 140 feet and 50 heads. how many sheep and chicken are there? there are sheep and chicken at the farm.