1.

#include<iostream>

using namespace std;

int main()

{

int year,s;

cout<<"Enter The Year: "<<endl;

cin>>year;

if(year%4==0)

{

if(year%100==0)

{

if(year%400==0)

cout<<"This is a loop year: "<<year;

else

cout<<"This is not a loop year: "<<year;

}

else

cout<<"This is a leap year: "<<year;

}

else

cout<<"This is not a leap year: "<<year;

return 0;

}

2.

#include<iostream>

using namespace std;

int main()

{

int a,b,c;

cout<<"Enter the two numbers: "<<endl;

cin>>a>>b;

c=a+b;

cout<<"Your total sum is: "<<c;

}

3.

#include<iostream>

using namespace std;

int main()

{

int n,i;

cout<<"Enter the input from the user: ";

cin>>n;

for(i=1;i<=10; i++)

{

cout<<"Here table value is: "<<n*i<<endl;

}

}

4.

#include<iostream>

using namespace std;

int main()

{

int a,b,c,d,temp,hcf,lcm;

cout<<"Enter two values: "<<endl;

cin>>c>>d;

a=c;

b=d;

while(b!=0)

{

temp=b;

b=a%b;

a=temp;

}

hcf=a;

lcm=(c*d)/hcf;

cout<<"HCF: "<<hcf<<endl;

cout<<"LCM : "<<lcm<<endl;

}