Question

8.5% of a barrel of oil is turned into plastic. A barrel of oil contains 42 gallons. How many gallons are NOT

turned into plastic?

Answer 1

Explanation:

as 8.5% of such a barrel are turned into plastic, that means 100 - 8.5 = 91.5% of such a barrel are not turned into plastic.

remember, 100% means "the whole".

therefore, any % number is always an expression of that many 1/100 of the whole.

and so,

42 × 91.5/100 = 42 × 0.915 = 38.43 gallons

out of the 42 gallons, 38.43 gallons are not turned into plastic.