Find the average of first N natural numbers

Write a program to find the Average of first N natural number.
Examples:

Input  : 10
Output : 5.5
1+2+3+4+5+6+7+8+9+10 = 5.5

Input  : 7
Output : 4.0
1+2+3+4+5+6+7 = 4

Prerequisite : Sum of first n natural numbers.



As discussed in previous post, sum of n natural number n(n+1)/2, we find the Average of n natural number so divide by n is n(n+1)/2*n = (n+1)/2. Here 1 if first term and n is last term.

C++

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// CPP Program to find the Average of first
// n natural numbers
#include <bits/stdc++.h>
using namespace std;
  
// Return the average of first n natural numbers
float avgOfFirstN(int n)
{
    return (float)(1 + n)/2;
}
  
// Driven Program
int main()
{
    int n = 20;
    cout << avgOfFirstN(n) << endl;
    return 0;
}

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Java

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// Java Program to find the Average of first
// n natural numbers
import java.io.*;
  
class GFG {
  
    // Return the average of first n 
    // natural numbers
    static float avgOfFirstN(int n)
    {
        return (float)(1 + n) / 2;
    }
  
    // Driven Program
    public static void main(String args[])
    {
        int n = 20;
        System.out.println(avgOfFirstN(n));
    }
}
  
/*This code is contributed by Nikita tiwari.*/

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Python3

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# Python 3 Program to find the Average 
# of first n natural numbers
  
# Return the average of first n
# natural numbers
def avgOfFirstN(n) :
    return (float)(1 + n) / 2;
  
# Driven Program
n = 20
print(avgOfFirstN(n))
  
# This code is contributed by Nikita Tiwari.

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C#

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// C#Program to find the Average of first
// n natural numbers
using System;
  
class GFG {
  
    // Return the average of first n 
    // natural numbers
    static float avgOfFirstN(int n)
    {
        return (float)(1 + n) / 2;
    }
  
    // Driven Program
    public static void Main()
    {
        int n = 20;
        Console.WriteLine(avgOfFirstN(n));
    }
}
  
/*This code is contributed by vt_m.*/

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PHP

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<?php
// PHP Program to find
// the Average of first
// n natural numbers
  
// Return the average 
// of first n natural 
// numbers
function avgOfFirstN($n)
{
    return (float)(1 + $n) / 2;
}
  
// Driver Code
$n = 20;
echo(avgOfFirstN($n));
  
// This code is contributed by Ajit.
?>

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Output:

10.5

Time Complexity : O(1)



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Improved By : jit_t



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