Question

Your car gets 22 miles per gallon.
Which proportion could you solve to determine how many gallons of gas, g, are needed to drive 108 miles?

Answer 1

To find out how many gallons of gas \( g \) are needed to drive 108 miles, you can set up a proportion based on the miles per gallon (mpg) your car gets. Since your car gets 22 miles per gallon, you can establish the following relationship:

\[
\frac{108 \text{ miles}}{g \text{ gallons}} = \frac{22 \text{ miles}}{1 \text{ gallon}}
\]

This proportion states that the ratio of miles driven to gallons used for your trip is the same as the ratio of miles per gallon for your car. You can cross-multiply to solve for \( g \):

\[
108 \text{ miles} \times 1 \text{ gallon} = 22 \text{ miles} \times g \text{ gallons}
\]

This simplifies to:

\[
108 = 22g
\]

You can then solve for \( g \) by dividing both sides by 22:

\[
g = \frac{108}{22}
\]

So the proportion that can be solved to determine how many gallons of gas are needed is:

\[
\frac{108}{g} = \frac{22}{1}
\]