WAP to Calculation of simple interest

/*WAP to Calculation of simple interest */

#include<stdio.h>
#include<conio.h>
main( )
{
 int   p, n ;
 float   r, si ; 

 p = 1000 ;
 n = 3 ;
 r = 4.5 ;

 /* formula for simple interest */
 si = p * n * r / 100 ;  

 printf ( "%f" , si ) ;
} 

Addition of two equations-FUN

Q: Addition of two equations.

equ1- Study=Don't Fail
equ2- Don't Study=Fail
Ans: Study+Don't Study = Fail+Don't Fail
=>Study(1+Don't)=Fail(1+Don't)
=>Study=Fail

WAP to Convert Decimal to Binary

/*Convert Decimal to Binary*/

#include<stdio.h>
#include<conio.h>
void main()
{
 clrscr();
 int a,b,x,y,i[5],j,r;
 printf("Enter  no.");
 scanf("%d",&a);
 x=a%2;
 y=a/2;
 b=(y*2)+(x);
 for(j=0;b!=0;b/=2)
 {
  i[j]=b%2;
  j++;
 }
 for(r=j-1;r>=0;r--)
 {
  printf("%d",i[r]);
 }
 getch();
}