Java chapter-1 practice set answer

                                                 Java chapter 1 question

Answer of all Question:

package com.ritesh;

import java.sql.SQLOutput;
import java.util.Scanner;

public class javachapter1 {
    public static void main(String[] args) {
        add();                                                         //Calling the function
        gpa();
       enter_name();
        kilometer();
        detect();

    }

    private  static  void add()     //question 1
    {
        System.out.println("Enter first number");
        Scanner sc=new Scanner(System.in);
        float n1=sc.nextFloat();
        System.out.println("Enter second number");
        Float n2=sc.nextFloat();
        System.out.println("Enter Third number");
        float n3= sc.nextFloat();
        float output=n1+n2+n3;
        System.out.println(output);

    }
    private static  void gpa() {  //question 2
        System.out.println("Enter mark you obtained  of java");
        Scanner gpa = new Scanner(System.in);
        float sub1 = gpa.nextFloat();

        System.out.println("Enter mark you obtained  of English");
        Float sub2 = gpa.nextFloat();

        System.out.println("Enter mark you obtained  of Physic");
        Float sub3 = gpa.nextFloat();

        System.out.println("Enter mark you obtained  of maths");
        Float sub4 = gpa.nextFloat();

        System.out.println("Enter mark you obtained  of biology");
        Float sub5 = gpa.nextFloat();

        float totalofall = sub1 + sub2 + sub3 + sub4 + sub5;
        if (totalofall<= 500) {
            System.out.println("You obtained " + totalofall + " out of 500 in your exam\n");

            float percentage = (totalofall / 500) * 100;
            System.out.println("You obtained " + percentage + " out of 100% in your exam\n");

            float gpa1 = (percentage / 100) * 4;
            System.out.println("Congratulation you score " + gpa1 + " In exam\n");
        }
        else
            System.out.println("Invalid input Please try again");
    }
    private  static  void enter_name ()//question 3
    {
        System.out.println("Enter you name");
        Scanner sc=new Scanner(System.in);
        String output=sc.nextLine();
        try
        {
            Integer.parseInt(output);
            System.out.println("Invalid keyword");
        }
        catch (NumberFormatException e) {
            System.out.println("\"Hello<"+output+">,have a good day");
        }




    }
    private  static void kilometer() //question 4
    {
        System.out.println("Enter the kilometer ");
        Scanner sc=new Scanner(System.in);
        double kilometer=sc.nextDouble();
        double covert=(kilometer/1.60934);
        System.out.println("Their are "+covert+" mile in"+kilometer);
    }
    private  static  void detect() //question 5
    {
        System.out.println("Enter the number");
        Scanner sc=new Scanner(System.in);
        String in=sc.nextLine();
        try
        {
            Integer.parseInt(in);
            System.out.println(in+" Is a integer");

        }
        catch (NumberFormatException e) {
            System.out.println(in + " Is not a integer");
        }
    }

}