def hotel_cost(nights):

return 140 * 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 = days * 40

if days >= 7:

cost -= 50

elif days >= 3:

cost -= 20

return cost

"It looks like rental_car_cost returns None instead of the correct amount (40) for 1 days."

Thanks in advance for any help!