python function as objects

Question

I totaly lost my understanding in the second function please can someone explain to me what the second function do and how
def add(x, y):
return x + y

def do_twice(func, x, y):
return func(func(x, y), func(x, y))

a = 5
b = 10

print(do_twice(add, a, b))

Answer 1

In this code, the second function gets 3 arguments.
func = add
x = 5
y = 10

Therefore, the second function returns
add(add(5,10), add(5,10))

and, the first function return
add(15, 15) ---> 30

Answer 2

The inner funcs in the return statement are the arguments for the outer func, and thats why it is done twice. It is one of the challenges. I could be wrong.