Transporter help please


#1

When i enter my code i get the warning "It looks like rental_car_cost returns 120 instead of the correct amount (100) for 3 days" and i dont know how. i worked it out and it seems like it would equal to 100, right?
heres my code:

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

#2


#3

this:

cost - 20

will not update the cost variable, look:

x = 30
print x # 30
print x - 10 # 20
print x # 30
x = x - 10
print x # 20

hope that helps


#4

ah yeah okay i got it thanks


#5