SUM OF A RANGE

#include<iostream.h>

#include<conio.h>

void main()

{

 int n, m, a=0, b=0;

 cout<<"Enter the starting number :";

 cin>>n;

 cout<<"Enter the last number :";

 cin>>m;

 a=n;

 int i=0;

 do

 {

  a=n+i;

  b=b+a;

  i++;

 }while(i<=m-n);

 cout<<"Sum of the range ="<<b;

 getch();

}

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OUTPUT: (click to enlarge the image)