1. Programming in C

2. #include <stdio.h> #include <conio.h>
Program to find an area and circumference of an area
#include <stdio.h>
#include <conio.h>
#include <math.h>
int main()
{int r;
float pi=3.14, area,ci;
printf("enter radius:");
scanf("%d", &r);
//area=pi*r*r;
area=pi*(pow(r,2));
printf("area of circle =%f \n ", area);
ci=2*pi*r;
printf(" circumference =%f",ci);
getch(); }

3. scanf("%d%d%d",&p,&r,&t); si=(p*r*t)/100;
Program to find the simple interest
int p,r,t,si;
printf("eneter principle, rate of interest & time to find simple interest: \n");
scanf("%d%d%d",&p,&r,&t);
si=(p*r*t)/100;
printf("simple interest=%d",si);
getch();

4. printf("enter marks of 5 subjects:");
Program to calculate sum of 5 subjects and find percentage
int s1,s2,s3,s4,s5,sum,total=500;
float per;
printf("enter marks of 5 subjects:");
scanf("%d%d%d%d%d",&s1,&s2,&s3,&s4,&s5);
sum=s1+s2+s3+s4+s5;
printf("sum=%d \n",sum);
per=(sum*100)/total;
printf("percentage =%f",per);

5. printf("eneter value of a&b: \n"); scanf("%d%d",&a,&b); a=a+b; b=a-b;
Program to swap two numbers without using a third variable
int a,b;
printf("eneter value of a&b: \n");
scanf("%d%d",&a,&b);
a=a+b;
b=a-b;
a=a-b;
printf("after swapping the value of a&b:%d\n%d",a,b);