Question

Before your trip to the mountains, your gas tank was ; full. When you returned home, the gas gaugeregistered ; of a tank. If your gas tank holds 18 gallons, how many gallons did you use to drive to themountains and back home?

Answer 1

To determine the total gallons used in the trip, let's solve the following first.

1. Initial gallon before the trip.

If the tank is 18 gallons when full and before the trip, it was 7/9 full, then, let's multiply 18 and 7/9 to get the exact number of gallons before the trip.

`18*(7)/(9)=(18)/(1)*(7)/(9)=(126)/(9)=14gal`

Hence, initially, there were 14 gallons before the trip.

2. Number of gallons after the trip

If the tank is 18 gallons when full and after the trip, it was now 1/3 of a tank, then, let's multiply 18 and 1/3 to get the exact number of gallons left after the trip.

`(18)/(1)*(1)/(3)=(18)/(3)=6gal`

After the trip, we have 6 gallons of gas remaining in the tank.

So, this means, 14 gal - 6 gal = 8 gallons of gas was used in driving to the mountain and back home.