3-8

 #include <iostream>
using namespace std;
class Student
{
public:
	Student(int n,float s):num(n),score(s){}
	void change(int n,float s)
	{
	 num=n;
	 score=s;
	}
	void display()
	{
	 cout<<num<<" "<<score<<endl;
	}
private:
	int num;
	float score;
};
int main()
{
 Student stud(101,78.5);
 void fun(Student &);
 fun(stud);
 return 0;
}
void fun(Student &stu)
{
 stu.display();
 stu.change(101,80.5);
 stu.display();
}