def rental_car_cost(days):

cost = 40 * days

if days >= 7:

return cost -= 50

elif days >= 3:

return cost -= 20

` return cost`

I do not get what I am doing wrong?????

def rental_car_cost(days):

cost = 40 * days

if days >= 7:

return cost -= 50

elif days >= 3:

return cost -= 20

` return cost`

I do not get what I am doing wrong?????

Make sure you are indenting properly

Also no need for the -= in the return cost.

And you need the else: statement for your return cost

```
def rental_car_cost(days):
cost = 40 * days
if days >= 7:
return cost - 50
elif days >= 3:
return cost - 20
else:
return cost
```

Every time after every "if/elif/else" you need return value so for this one you need write "return cost"

This is right code:

```
def rental_car_cost(days):
cost = days*40
if days >= 7:
cost -= 50
return cost
elif days >= 3:
cost -= 20
return cost
else:
return cost
```