Codeacademy Car Rental

Codeacademy Car Rental

days = int(raw_input("How many days do you want to rent da car for?"))
def rental_car_cost(days):
if days < 3:
return days * 40
if days <= 3 and days >= 7:
return ((days * 40)-20)
elif days > 7:
return ((days*40) -50)
print rental_car_cost(days)
Thanks for your help in advance. What I am trying to do is get this
function to return:
The cost of a car that is rented for 2 or less days at 40 a day.
The cost of car a car that is rented between 3 and 7 days with a discount
of 20.
The cost of a car rented for more than 7 days with a discount of 50.
However, when I put in 35 for days instead of 1,350, I get none. And when
I put in 5 for days...I get none. Ideas?