At a corner gas station, the revenue R varies directly with the number g of gallons of gasoline sold. If the revenue is

At a corner gas station, the revenue R varies directly with the number g of gallons of gasoline sold. If the revenue is $44.50 when the number of gallons sold is 10, find a linear equation that relates revenue R to the number g of gallons of gasoline. Then find the revenue R when the number of gallons of gasoline sold is 15.5.

Solution:

As the question mentioned the direct relationship between the quantities, hence

10 gallons of gasoline sold = $44.50

15.5 gallons of gasoline sold = $x

by cross multiplication, we get that

10x = 15.5 * 44.50

which implies that

x = 68.975

Thus by $ 68.975 revenue is obtained by selling 15.5 gallons of gasoline.