5. Pull it all together

no matter what I try it keep saying, "rental_car_cost(3) returned 120 instead of the correct value 100

```
def hotel_cost(nights):
return (nights) * 140
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):
return (days) * 40
if days >= 7:
cost -= 50
elif days >= 3:
cost -= 80
else:
return cost
def trip_cost(city, days):
return hotel_cost(nights) + plane_ride_cost(city) + rental_car_cost(days)
```