Let us say that the number is x.
So the first step that Julio do is to cube the number so
that:
x^3
Then the next he did was take cube root of the number, so
that:
(x^3)^(1/3)
Solving this would result in:
x^(3/3) = x^1 = x
Since he ends up with 20, therefore:
x = 20
Julio started and ended with the same number which is 20.
