Fuel Economy A woman drives an SUV that gets 10 mi/gal (mpg). Her husband drives a hybrid that gets 60 mpg. Every week, they travel the same number of miles. They want to improve their combined mpg. They have two options on how they can improve it.
Option 1: | They can tune the SUV and increase its mileage by 1 mpg and keep the hybrid as it is. |
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Option 2: | They can buy a new hybrid that gets 80 mpg and keep the SUV as it is. |
Which option will give them a better combined mpg?
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The combined gas mileage is total miles divided by total gallons. |
Let x = number of miles each drives in a week. |
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Define a variable and describe each option. |
Option 1
Tuned SUV gets 11 mpg. SUV gets 10 mpg. |
Option 2
SUV gets 10 mpg. New hybrid gets 80 mpg. |
The gallons used by each vehicle are
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Find the LCD of the fractions in each expression. Multiply the numerator and denominator by the LCD. |
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Distribute and simplify. |
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Round the ratios and compare them. |
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Option 1 gives the better combined mpg. |