Question

Which of the following is the most appropriate to describe the rate of the cost of gasoline

Answer 1

A.Dollars per gallon, because the dependent quantity is the gallons.
B. Dollars per gallon, because the dependent quantity is the dollars.
C.Gallons per dollar, because the dependent quantity is the gallons.
D.Gallons per dollar, because the dependent quantity is the dollars

Answer 2

in (y) per (x), y is the dependent variable and x is the independent variable

in this case, the dollars depends on the # of gallons. (when you go to fill up your tank, you will usually fill based on the # of gallons, and then determine the cost afterwards.*). therefore, cost of gas is expressed in dollars per gallon

*yes, you *can* do it the other way around, where you pay a certain amount of money upfront and determine the # of gallons from that, but this method is much less common and thus not the way gas prices are written