C++ Exercises: Display the n terms of even natural number and their sum

Last update on April 07 2025 12:59:41 (UTC/GMT +8 hours)

21. Sum of n Even Natural Numbers

Write a C++ program that displays the sum of the n terms of even natural numbers.

Visual Presentation:

Sample Solution:-

C++ Code :

#include <iostream> // Including input-output stream header

using namespace std; // Using standard namespace to avoid writing std::

int main() // Start of the main function
{
    int i, n, sum = 0; // Declaration of integer variables 'i' (loop counter), 'n' (user input for the number of terms), 'sum' (sum of even natural numbers)

    cout << "\n\n Display n terms of even natural number and their sum:\n"; // Display message on the console
    cout << "---------------------------------------------------------\n";
    cout << " Input number of terms: "; // Prompt the user to input the number of terms
    cin >> n; // Read the input value as the number of terms

    cout << "\n The even numbers are: "; // Display message indicating the list of even numbers

    for (i = 1; i <= n; i++) // Loop for 'n' terms
    {
        cout << 2 * i << " "; // Print the even numbers by formula 2 * 'i'
        sum += 2 * i; // Add the even number to the sum variable
    }

    cout << "\n The Sum of even Natural Numbers up to " << n << " terms: " << sum << endl; // Display the sum of even numbers up to 'n' terms
}

Sample Output:

Display n terms of even natural number and their sum:                 
---------------------------------------------------------              
 Input number of terms: 5                                              
 The even numbers are: 2 4 6 8 10                                        
 The Sum of even Natural Numbers upto 5 terms: 30  

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to display the first n even natural numbers and calculate their sum.
• Write a C++ program that reads n and prints even numbers from 2 to 2n, then computes their total sum.
• Write a C++ program to generate and sum the first n even numbers using a for loop with arithmetic progression.
• Write a C++ program that outputs an array of n even numbers and then prints the aggregate of these numbers.

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