Question

A car has a 16-gallon fuel tank. When driven on a highway, it has a gas mileage of 30 miles per gallon. The gas mileage (also called "fuel efficiency") tells us the number of miles the car can travel for a particular amount of fuel (one gallon of gasoline, in this case). After filling the gas tank, the driver got on a highway and drove for a while.

How many gallons are left in the tank when the car has traveled the following distances on the highway?

90 miles

Answer 1

13 gallons

Set It Up

If the car is able to travel 30 miles per gallon and has a 16-gallon fuel tank, its total fuel efficiency is found by evaluating the product of the two factors.

Therefore, we can multiply 30 by 16 and find the total mileage that the car is equipped to travel:

`30*16=480`

Solve

Now, assuming that the car has a full tank of gas, it travels 90 miles on the highway. We can find out the remaining fuel efficiency by subtracting 90 miles from the maximum fuel efficiency:

`480-90=390`

Then, since the car can travel 30 miles per gallon, divide this fuel efficiency by 30 miles to find the remaining gallons in the tank:

`\displaystyle (390)/(30) = 13`

Final Answer

`\boxed{\bold{13 \ gallons}}`