Learn
Taking a Vacation
Pull it Together

Great! Now that you’ve got your 3 main costs figured out, let’s put them together in order to find the total cost of your trip.

``````def double(n):
return 2 * n

def triple(p):
return 3 * p

return double(a) + triple(b)``````
1. We define two simple functions, `double(n)` and `triple(p)` that return 2 times or 3 times their input. Notice that they have `n` and `p` as their arguments

2. We define a third function, `add(a, b)` that returns the sum of the previous two functions when called with `a` and `b`, respectively. Notice that even though the names of the parameters for `add(a, b)` are different than the names of the parameters for `double(n)` and `triple(p)` we can still pass them into those functions as arguments

### Instructions

1.

Below your existing code, define a function called `trip_cost` that takes two parameters, `city` and `days` and returns the sum of calling the `rental_car_cost(days)`, `hotel_cost(days - 1)`, and `plane_ride_cost(city)` functions.

Notice that we changed the argument of `hotel_costs()` from `nights` to `days - 1`. Since we want `trip-cost` to only depend on two parameters, we have to convert the variable `nights` into `days`. If you are going to be staying somewhere, the number of nights you stay there is one less than the number of days you were there (imagine a weekend trip to visit family, you leave Saturday and return Sunday, so you visit for two days, but only stay for one night).