I give up. Here's what happens to be the last of my attempts at the code:

def hotel_cost(nights):

return 140.0 * nights

def plane_ride_cost(city):

if city == "Charlotte":

return 183

elif city == "Tampa":

return 220

elif city == "Pittsburgh":

return 222

elif city == "Los Angeles":

return 475

def rental_car_cost(days):

cost = 40 * days

if days >= 7:

cost -= 50

elif days >= 3:

cost -= 20

return cost

def trip_cost(city, days):

return hotel_cost(nights) + plane_ride_cost(city) + rental_car_cost(days)

print trip_cost("Pittsburgh", 10)