Solutions

import java.util.*;

class BookFair

{

    String Bname;

    double price,amount;

    BookFair()    

    {

        Bname="";

        price=0.0d;

        amount=0.0;

    }

    void input()

    {

        Scanner sc=new Scanner (System.in);

        System.out.print("Enter the  Book name: ");

        Bname=sc.nextLine();

        System.out.print("Enter the  Price of the Book : ");

        price=sc.nextDouble();

    }

    void calculate()

    {

        if(price<=1000)

            amount=price*2/100;

        else if(price<=3000)

            amount=price*10/100;

        else

        amount=price*15/100;

    }

    void display()

    {

        System.out.println("The Name of the Book is "+Bname);

        System.out.println("The Price of the Book is "+price);

        System.out.println("The Actual Amount to be paid is "+amount);

    }

    void main()

    {

        BookFair ob=new BookFair();

        ob.input();

        ob.calculate();

        ob.display();

    }

}

==================================================

import java.util.Scanner;

class ElectricityBill

{

    String n;

    int units;

    double bill;

    ElectricityBill()

    {

        n="";

        units=0;

        bill=0.0d;

    }

    void accept()

    {

        Scanner sc = new Scanner(System.in);

        System.out.print("Enter the Name of the Customer:");

        n = sc.next ();

        System.out.print("Enter the Number of Units Consumed");

        units = sc.nextInt();

    }

    void calculate()

    {

        if(units<=100)

            bill = 10 * units;

        else if(units<=200) //next 100 units

            bill = 10 * 100 + (units - 100) * 15;

        else if(units<=300) //next 100 units

            bill = 10 * 100 + 100 * 15 + (units - 200) * 20;

        else //above 300 units

        {

            bill = 10*100 + 100*15 + 100*20 + (units-300) * 25;

            bill = bill + bill * 2.5 /100; //surcharge 2.5%

        }

    }

    void display()

    {

        System.out.println("Name of the Customer : " + n);

        System.out.println("Number of Units Consumed : " + units);

        System.out.println("Bill Amount: " + bill);

    }

    public static void main()

    {

        ElectricityBill obj = new ElectricityBill();

        obj.accept();

        obj.calculate();

        obj.display();

    }

}