So i think i have everything correct by im not sure it keeps popping up errors:

def hotel_cost(nights):

`return 140 * nights`

def hotel_cost(nights):

return 140*nightsdef 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):`rentalcarcost = 40 * days if days >= 7: return rentalcarcost - 50 elif days >= 3: return rentalcarcost -20 else: return rentalcarcost`

def trip_cost(city, days):

`trip_cost = rental_car_cost(days) + hotel_cost(nights) + plane_ride_cost(city)`

and here is the error:

Oops, try again. trip_cost('Charlotte', 0) raised an error: global name 'nights' is not defined