What is the output of the question with explanation?

Question

int a=20;
int &n=a;
n=a++;
a=n++;
cout<<a<<","<<n;

Answer 1

You using reference From now on, you can use both of these variables interchangeably.
The following assignments will give the same effect:
n = a++;
20 = 20;
a = n++;
21 = 20;
So, now a is equals 20 the same as n.

Answer 2

https://code.sololearn.com/cXtLwzF7ZDeu/?ref=app

Answer 3

n =a++ in this line a post increment bcoz n is reference type then both value are 21 na
Why 20 20