Output is 16 but how ??? Anyone can explain

Question

def test(func,arg):
return func (func (arg))
def mult(x):
return x * x
print(test(mult,2))

Answer 1

Passing function as argument.. So just replace func with mult and check...
return func( func(arg))
=> mult(mult(2)
=>mult(4)
=>16

Answer 2

Thanks a ton sir

Answer 3

Sorry sir

Answer 4

Sagar Kumar you're welcome..

Edit:

Answer 5

Sagar Kumar no problem..