Question

Suppose your car gets 28 miles per gallon of gasoline, and you are driving at 55 miles per hour. Using unit analysis, find the amount of gas you use every hour.

Answer 1

Answer:

1 27/28 ≈ 1.964 gallons/hour

Step-by-step explanation:

You want gallons in the numerator of your unit rate, but that unit is in the denominator of the mileage rate. So, the computation must involve division by 28 mpg. Hours is already in the denominator of 55 mph, so the computation will involve multiplication by that rate.

... (55 mi/h)/(28 mi/gal) = (55 mi/h)·(1 gal/(28 mi)) = 55/28 gal/h

... = 1 27/28 gal/h