Q:

# C program to find the sum of Natural Number/Factorial of Number of all natural numbers from 1 to N

#### C program to find the sum of Natural Number/Factorial of Number of all natural numbers from 1 to N.Series: 1/1! + 2/2! + 3/3! + 4/4! + ... N/N!

``````/*
This program will find the sum of Natural
Number/Factorial of Number of all natural numbers from 1 to N.
*/

#include<stdio.h>

/*function to find factorial of the number*/
unsigned long factorial(int num)
{
int i;
/*always assign 1, if variable multiplies with values*/
unsigned long fact=1;

/*multiply num*num-1*num-2*..1*/
for(i=num; i>=1; i--)
fact= fact*i;

/*return factorial*/
return fact;
}

int main()
{
int i,N;
float sum;

printf("Enter the value of N: ");
scanf("%d",&N);

/*set sum by 0*/
sum=0.0f;

/*calculate sum of the series*/
for(i=1;i<=N;i++)
sum = sum + ( (float)(i) / (float)(factorial(i)) );

/*print the sum*/

printf("Sum of the series is: %f\n",sum);

return 0;
}``````
```    Enter the value of N: 10
Sum of the series is: 2.718282
```