We are given a figure of a cylinder with two known lengths. We are to determine whether which of them is the height of the cylinder.
We know that the base of the cylinder is round so the length mentioned on the round base is its diameter.
While the other length running from the top to bottom (or from left to right as shown in the picture) is the height of the cylinder which is 22 inches.
So you get 30.1 miles out of one gallon of gas, therefore you multiply the 30.1 by 7 30.1 x 7 = 210.7 this means that you would travel 210.7 miles on seven gallons of gas