Iterative Constructs in Java

Chapter 9

Iterative Constructs in Java

Class 10 - Logix Kips ICSE Computer Applications with BlueJ

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Java Program: Compute Series Sum

28. Write a program to read the number x using the Scanner class and compute the series:

Sum = x/2 + x/5 + x/8 + x/11+ ..... + x/20

The output should look like as shown below:

Enter the value of x: 10
Sum of the series is: 10.961611917494269

Program Title: Compute Series Sum

\[ Sum = \frac{x}{2} + \frac{x}{5} + \frac{x}{8} + \frac{x}{11} + \cdots + \frac{x}{20} \]

import java.util.Scanner;
 
public class SeriesSum {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
 
        System.out.print("Enter the value of x: ");
        double x = sc.nextDouble();
 
        double sum = 0.0;
 
        // Denominators: 2, 5, 8, 11, 14, 17, 20 (increasing by 3)
        for (int denominator = 2; denominator <= 20; denominator += 3) {
            sum += x / denominator;
        }
 
        System.out.println("Sum of the series is: " + sum);
 
        sc.close();
    }
}
 

Sample Input / Output
Enter the value of x: 10
Sum of the series is: 10.961611917494269

📝 Explanation

1. Denominators in the series follow an arithmetic progression: 2, 5, 8, 11, 14, 17, 20
• Difference between terms = 3
2. Each term = x / denominator
3. Loop through the denominators and add each term to the sum
4. Print the final sum as double to retain precision.