#include<stdio.h>

#include<conio.h>

main()

{

int i,n,d,a,tn,sum=0;

clrscr();

printf("\n enter the first term of the A.P.");

scanf("\n %d",&a);

printf("\n enter the difference of A.P.");

scanf("\n %d",&d);

printf("\n enter the total term in A.P.");

scanf("\n %d",&n);

sum=(n*(2*a+(n-1)*d))/2;

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

printf("\n sum of series =");

for(i=a;i<=tn;i=i+d);

{

if(i!=tn)

{

printf("%d+",i);

}

else

{

printf("\n %d=%d",i,sum);

}

}

return (0);

}

output:-

first term of A.P. is a=3

difference of A.P.is d=5

total term of A.P. is n=5

sum of the series= 3+8+13+18+23=65