What will be the output of the following program?

#include<iostream.h> 
class BixTest
{
    public:
    BixTest(int &x, int &y)
    {
        x++;
        y++;
    } 
};
int main()
{
    int a = 10, b = 20;
    BixTest objBT(a, b); 
    cout<< a << " " << b; 
    return 0; 
}

Which of the following statement is correct about the program given below?

#include<iostream.h> 
int main()
{
    int m = 2, n = 6;
    int &x = m++;
    int &y = n++;
    m = x++; 
    x = m++;
    n = y++;
    y = n++;
    cout<< m << " " << n; 
    return 0; 
}

Which of the following statement is correct about the program given below?

#include<iostream.h> 
int main()
{
    int m = 2, n = 6;
    int &x = m;
    int &y = n;
    m = x++; 
    x = m++;
    n = y++;
    y = n++;
    cout<< m << " " << n; 
    return 0; 
}

Which of the following statement is correct about the program given below?

#include<iostream.h> 
int main()
{
    int x = 0;
    int &y = x; y = 5; 
    while(x <= 5)
    {
        cout<< y++ << " ";
        x++;
    }
    cout<< x; 
    return 0; 
}

Which of the following statement is correct about the program given below?

#include<iostream.h> 
int main()
{
    int x = 10, y = 20;
    int *ptr = &x;
    int &ref = y;

    *ptr++;
     ref++;    

    cout<< x << " " << y;
    return 0; 
}