s=80+75+70+........

 

s=80+75+70+........

//s=80+75+70+........

#include<stdio.h>

main()

{

    int n,a=80,d=-5,sum=0,term;

    printf("ENTER N=");

    scanf("%d",&n);

    term=a+(n-1)*d;

    for(a=80;a>=term;a=a-5)

    {

        sum=sum+a;

    }

    printf("ANS=%d",sum);

}