We can use proportions to get us started. For reference, we will call our answer
x.
For every 26 miles the car moves on the highway, it consumers one gallon of gas. Thus, for 247 miles the car moves on the highway, it consumes x gallons of gas. We can set these rates equal to each other to determine x.
In other words,

. To solve for x, we can multiply both sides of the equation by x:

Now, let's divide both sides of the equation by 26 to single out our x-value, since it is what we are looking for:
x = 9.5
Thus,
9.5 gallons of gas were used.