What goes in each drop down menu?

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

What’s the answer ? use the picture to see the problem

Indicate the formula for the following conditions: p^c(n,r)=