When renting a car, the cost per mile is inversely proportional to the number of miles driven. at zippy car rentals, if the standard model car is driven for 300 miles, then the cost per mile is $0.25. at zippy car rentals, the constant of variation is for a standard car rental. if that rental car is driven for 375 miles, then the cost per mile is $ .

Part a)

Let C represent the cost per mile and m represent the number of miles driven. The cost per mile is inversely proportional to the number of miles driven

This means:



where, k is the constant of proportionality. 

For m = 300 miles, c = $0.25
Using the values in equation:

k = 300 * 0.25 = 75

Thus the constant of proportionality is 75. So the equation can be written as:



Part b)

The car is driven for 375 miles. We are to calculate the cost per mile C.

Using the values in the formula, we get:



Thus the for a standard car rental, if that rental car is driven for 375 miles, then the cost per mile is $ 0.20