SOLUTION: A certain car uses 15 gal of gasoline in 3 h. If the rate of gasoline consumption is constant, how much gasoline will the car use on a 35-hour trip?

Question 1202459: A certain car uses 15 gal of gasoline in 3 h. If the rate of gasoline consumption is constant, how much gasoline will the car use on a 35-hour trip?
Found 4 solutions by ikleyn, greenestamps, josgarithmetic, math_tutor2020:
Answer by ikleyn(52864)   (Show Source): You can put this solution on YOUR website!
.

Write a proportion = = . From this proportion, find x = = 5*35 = 175 gallons. ANSWER

Solved.

Notice that the proportion says that the rate of the gasoline consumption per hour remains the same (remains constant).

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For introductory lessons on proportions, see the lessons
    - Proportions
    - Using proportions to solve word problems
    - Typical problems on proportions
    - Using proportions to estimate the number of fish in a lake
    - HOW TO algebraize and solve these problems using proportions
in this site.

Learn the entire subject from there.

Happy learning ( ! )

Answer by greenestamps(13204)   (Show Source): You can put this solution on YOUR website!

Using a proportion, as the other tutor did, is one good formal way for solving the problem.

A slightly less formal way, given that the rate of fuel consumption is constant, is to multiply the given number of gallons of gas by the ratio of the two times:

ANSWER: 175 gallons

And a third easy solution method is to use the given data to determine the rate of fuel consumption in gallons per hour and multiply that number by 35 hours:

The actual calculation in all three solution methods is the same; so the choice of which method is up to the student -- find the method that "works" for you an use it.

Answer by josgarithmetic(39627)   (Show Source): You can put this solution on YOUR website!
15 gallons fuel in 3 hours;
35 hours of travel ;

Answer by math_tutor2020(3817)   (Show Source): You can put this solution on YOUR website!

Answer: 175 gallons

Work Shown
15 gal : 3 hr
15/3 gal : 3/3 hr .... divide both sides by 3
5 gal : 1 hr
35*5 gal : 35*1 hr .... multiply both sides by 35
175 gal : 35 hr

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