a. Give a brief description of the problem (Specification and assumptions) public class electricbill { public static void main(String[] args) { int presentReading = 0, previousReading = 0; Scanner kbd = new Scanner(System.in); String consumer = ""; // to hold name of consumer char cType = 'x'; // to hold type of consumer int nCMUsed; // to hold number of units consumed int minCMResidential = 12; // to hold cut-off for minimum Bill // for residential consumers double minBillResidential = 98; // minimum bill for <= 12 units float rateResidential = 8.1583F; // cost of 1 unit above the min. consumption int minCMCommercial = 7; // to hold cut-off for minimum Bill for commercial consumers double minBillCommercial = 600.00; // minimum bill for <= 20 units used float rateCommercial = 50.00F; // cost of 1 unit above the min. // consumption for commercial consumers double amountDue = 0.0; // to hold the amount due showIntroduction(); // prompt message for name System.out.print("Enter the name of the electricity consumer: "); // input name consumer = kbd.nextLine(); // store previous reading using method readPreviousReading(); previousReading = readPreviousReading(); // store cuurent reading using method readPresentReading(); presentReading = readPresentReading(previousReading); // store electricity consumption nCMUsed = presentReading - previousReading; // store consumer type cType = readTypeOfConsumer(); // compute due amount amountDue = computeAmountDue(nCMUsed, cType, minCMResidential, minBillResidential, minCMCommercial, minBillCommercial, rateResidential, rateCommercial); showBill(consumer, cType, previousReading, presentReading, nCMUsed, amountDue); System.exit(0); } // end of main method public static void showBill(String n, char t, int previous, int present, int c, double amount) { System.out.println("-------------------------------"); System.out.println("Electricity Billing Statement"); System.out.println("Name of Consumer: " + n); System.out.print("Type of consumer: "); if (Character.toLowerCase(t) == 'r') System.out.println("Residential"); if (Character.toLowerCase(t) == 'c') System.out.println("Commercial"); System.out.println("Meter reading last month = " + previous + " units "); System.out.println("Meter reading this month = " + present + " units"); System.out.println("Units Consumed = " + c + " units"); System.out.println("Amount Due = ₱ " + amount); return; } public static void showIntroduction() { System.out.println(); System.out.println("This program will prepare a bill for a electricity " + "distribution consumer."); System.out.println("--------------------------------------------------------------------------"); System.out.println("You will be asked to enter the name of the " + "consumer,\n\tthe electricity meter reading last month, " + "\n\t and the electricity reading this month."); System.out.println("---------------------------------------------------------------------------"); return; // optional since return type of the method is void } public static int readPreviousReading() { int reading = 0; Scanner kbd = new Scanner(System.in); do { System.out.print("Enter the meter reading last month: "); // input previous reading reading = Integer.parseInt(kbd.nextLine()); // if less than 0 if (reading < 0) { System.out.println("The meter reading cannot be negative."); } } while (reading < 0); // loop until value is positive return reading; } public static int readPresentReading(int previous) { int reading = 0; Scanner kbd = new Scanner(System.in); do { System.out.print("Enter the meter reading for this month: "); // input current reading reading = Integer.parseInt(kbd.nextLine()); // check if current reading is less than previous reading if (reading < previous) { System.out.println("Invalid datum entry! The present reading " + "must be greater than the previous reading."); } } while (reading < previous); // loop until current > previous return reading; } public static char readTypeOfConsumer() { char t = 'x'; Scanner kbd = new Scanner(System.in); do { System.out.print("Enter the type of the consumer (type r " + "for residential or c for commercial): "); // input consumer type String input = kbd.nextLine(); // store first character of input t = input.charAt(0); if (t != 'r' && t != 'R' && t != 'c' && t != 'C') { System.out.println("The valid types are r for residential " + "and c for commercial."); } } while (t != 'r' && t != 'R' && t != 'c' && t != 'C'); // loop until type is valid return t; } public static double computeAmountDue(int c, char t, int min1, double minB1, int min2, double minB2, float rate1, float rate2) { double amount = 0; switch (t) { case 'r': case 'R': if (c <= min1) { amount = minB1; } else { amount = minB1 + (c - min1) * rate1; } break; case 'c': case 'C': if (c <= min2) { amount = minB2; } else { amount = minB2 + (c - min2) * rate2; } } return amount; } } // end of class