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math - equation - auto expense - cost per mile











































A car’s gas tank holds 15 gallons. The car can be driven 400 miles on a single tank of gas.

a. Write an equation which shows the relationship between the number of gallons of gasoline and the distance the car can be driven.
b. How far can the car be driven if there is only 6.3 gallons of gas (rather than 15 gallons)?
c. If the car is driven 14,000 miles in one year, how many gallons of gasoline were used?
d. If the gasoline costs $4.10 per gallon, how much did it cost to purchase gasoline for the entire year.
e. Compute miles per gallon.
f. What is the gasoline cost per mile?


Comments for math - equation - auto expense - cost per mile

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Jun 27, 2012
auto expense - cost per mile
by: Staff



The answer:



Write an equation which shows the relationship between the number of gallons of gasoline and the distance the car can be driven.

Use a proportion to answer this question:

(x miles) / (y gallons) = (400 miles) / (15 gallons)

[(x miles) / (y gallons)] * (y gallons) = [(400 miles) / (15 gallons)] * (y gallons)

(x miles) * [(y gallons) / (y gallons)] = [(400 miles) / (15 gallons)] * (y gallons)

(x miles) * 1 = [(400 miles) / (15 gallons)] * (y gallons)

(x miles) = 26.6667 * (y gallons)

>>> miles car can be driven = 26.6667 * (gallons of gasoline)



How far can the car be driven if there is only 6.3 gallons of gas (rather than 15 gallons)?

miles car can be driven = 26.6667 * (gallons of gasoline)

miles car can be driven = 26.6667 * (6.3 gallons)

>>> miles car can be driven on 6.3 gallons of gasoline = 168 miles



If the car is driven 14,000 miles in one year, how many gallons of gasoline were used?

(miles car can be driven) = 26.6667 * (gallons of gasoline)

(miles car can be driven) / 26.6667 = 26.6667 * (gallons of gasoline) / 26.6667

(miles car can be driven) / 26.6667 = (gallons of gasoline) * (26.6667 / 26.6667)

(miles car can be driven) / 26.6667 = (gallons of gasoline) * 1

(miles car can be driven) / 26.6667 = (gallons of gasoline)

(gallons of gasoline) = (miles car can be driven) / 26.6667

(gallons of gasoline) = (14,000 miles) / 26.6667

(gallons of gasoline) = 524.999

>>> gallons of gasoline needed to drive 14,000 miles = 524.999 gallons



If the gasoline costs $4.10 per gallon, how much did it cost to purchase gasoline for the entire year.

Cost of gasoline = $4.10 * (524.999 gallons)

Cost of gasoline = $2,152.50

>>> Cost of gasoline for entire year = $2,152.50



Compute miles per gallon.

Miles per gallon = (400 miles) / (15 gallons)

Miles per gallon = 26.6667 miles per gallon

>>> fuel efficiency (mpg) = 26.6667 miles per gallon



What is the gasoline cost per mile?

Cost per mile = (cost for entire year) / (miles driven for entire year)

Cost per mile = ($2,152.50) / (14,000 miles)

Cost per mile = $0.15375 per mile

>>> Cost of gasoline per mile = 15.375 ¢ per mile







Thanks for writing.

Staff
www.solving-math-problems.com


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