3-7（2）

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