Question

One car traveled 840 miles on 30 gallons of gas. Another

car used 36 gallons of gas to travel 1008 miles. What proportion could you write to see if they are using fuel at the same rate?
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Answer 1

For each car, we want to compare the amount of miles to gallons. Thus, our proportion would appear as follows:

840 miles / 30 gallons = 1008 miles / 36 gallons

To find out if these proportions are equivalent, or the cars are using fuel at the same rate, we can cross-multiply, as shown below.

30240 = 30240

Because the numbers are equal when we cross-multiply, the cars are using fuel at the same rate.

Hope this helps!! :)