The function C(n) below relates the number of bushels of apples picked at a
pick-your-own orchard to the final cost for the apples.
It takes as input the number of bushels of apples picked after paying an entry
fee to an orchard and returns as output the cost of the apples (in dollars).
C(n) = 15n + 30
Which equation below represents the inverse function N(C), which takes the
cost of the apples as input and returns the number of bushels picked as
output?