Question

Christian is driving on a long road trip. He currently has 12 gallons of gas in his car. Each hour that he drives, his car uses up 1.25 gallons of gas. How much gas would be in the tank after driving for 6 hours? How much gas would be left after tt hours?Gas left after 6 hours: Gas left after t hours:

Answer 1

Given:

Initial gas - 12 gallons

Uses 1.25 gallons every hour

Find: gas remaining in the tank after 6 hours and t hours.

Solution:

a) after 6 hours

If 1.25 gallons of gas is used up every hour, then we can multiply 1.25 by 6 to determine the total amount of gas used after 6 hours.

`1.25gal*6hr=7.5gal`

After 6 hours, 7.5 gallons of gas were already used.

The remaining gas in the car would be:

`12gal-7.5gal=4.5gal`

After 6 hours of driving, only 4.5 gallons of gas remain in the tank.

b. after t hours

What we did above is we subtracted the result of the gallons used after 6 hrs from 12 gallons. Hence, the formula for solving the gas left after t hours is:

`\begin{gathered} 12gal-(1.25* t\text{ }hour) \\ or\text{ }just \\ 12-1.25t \end{gathered}`

Gas left after t hours is 12 - 1.25t.