ICSE Class 10 COMPUTER APPLICATIONS previous year paper (2019)

Question 3. [2 marks each] 

(a) Write a Java expression for the following:
               | x²+2xy |
(b) Write the return data type of the following functions:
               (i) startsWith( )
               (ii) random( )
(c) If the value of basic=1500, what will be the value of tax after the following statement is executed?
                 tax = basic>1200 ? 200 :100;
(d) Give the output of following code and mention how many times the loop will execute?

int i;
for( i=5 ; i>=1 ;i--)
{
    if(i%2 ==1)
      continue;
    System.out.print( i+ '' '');
}

(e) State a difference between call by value and call by reference. 
(f) Give the output of the following:
               Math.sqrt(Math.max(9,16))
(g) Write the output for the following:

String s1 = ''phoenix''; String s2 =''island'' ;
System.out.println (s1.substring(0).concat (s2.substring(2) ) );
System.out.println(s2.toUpperCase());

(h) Evaluate the following expression if the value of x=2, y=3 and z=1.
               v=x+ –z+ y++ +y
(i) String x[] = {“Artificial intelligence”, “IOT”, “Machine learning”, “Big data”};
          Give the output of the following statements:
                  (i) System.out.println(x[3]);
                  (ii) System.out.println(x.length);
(j) What is meant by a package? Give an example.

Ans. 
(a)  Math.abs(x*x +2*x*y)
       Math.abs(Math.pow(x,2)+ 2*x*y)
(b) (i) boolean
       (ii) double
(c) tax = 200
(d) 4 2
       five times loop will execute
(e)

Call By Value	Call by Reference
Works with immutable type (int, float, String, Tuple)	Works with mutable type (list, dictionary)
When mutable types are passed then if the value is copied in formal parameters	When immutable types are passed then the reference of the value is passed
Any change in formal parameters does not change the actual parameter in the main function	If any change is done inside the function, then the value in the main program is changed.
e.g. def power (n): n = n**2 a = 4 power(a) print (a) // This will print 4 only	def power (n): n[1] = n[0]**2 a = [4,0] power(a) print (a) // This will print [4,16]

(f) 4.0
(g) phoenixland
      ISLAND
(h) v = 9
(i) (i) Big data
     (ii) 4
(j) Package in Java is a mechanism to encapsulate a group of classes, sub packages and interfaces
Example: java.lang
                  java.util
                  java.io

SECTION B (60 Marks)
Attempt any four questions from this Section

Question 4. [15 marks]

Design a class name ShowRoom with the following description:

class	ShowRoom
Instance variables / Data members:
String name	To store the name of the customer
long mobno	To store the mobile number of the customer
double cost	To store the cost of the items purchased
double dis	To store the discount amount
double amount-	To store the amount to be paid after discount
Member methods:
ShowRoom()	default constructor to initialize data members
void input ()	To input customer name, mobile number, cost
void calculate ()	-To calculate discount on the cost of purchased items, based on given criteria
Void display ()	To display customer name, mobile number , amount to be paid after discount.

                                   Cost                                                                      Discount
                                                                                                           (in percentage)
Less than or equal to ₹ 10000                                                              5%
More than ₹10000 and less than or equal to ₹ 20000                  10%
More than ₹ 20000 and less than or equal to ₹ 35000                 15%
More than ₹ 35000                                                                                20%
Write a main method to create an object of the class and call the above member methods.
Ans. 

import java.util.*;
class ShowRoom
{
   String name;
   long mobno;
   double cost;
   double dis;
   double amount;
   ShowRoom( )
   {
     name = " ";
     cost=0;
     mobno=0;
     dis = 0.0;
     amount=0.0;
  }
  void input()
  {
    Scanner sc = new Scanner(System.in);
    System.out.println("enter name, mobile no and cost");
    name=sc.next();
    mobno=sc.nextLong();
    cost=sc.nextDouble();
  }
  void calculate()
  {
     if(cost <=10000)
     {
        dis=0.05*cost;
     }
     else if(cost >10000 && cost <=20000)
     {
        dis=0.1*cost;
     }
     else if(cost >20000 && cost <=35000)
     {
        dis=0.15*cost;
     }
     else
     {
        dis=0.2*cost;
     }
     amount = cost - dis;
   }
   void display()
   {
      System.out.println("Name is :"+name);
      System.out.println("Mobile no is :"+mobno);
      System.out.println("Amount :"+ amount);
   }
   public static void main (String arg[])
   {
      ShowRoom ob =new ShowRoom();
      ob.input();
      ob.calculate();
      ob.display();
   }
}

Question 5. [15 marks]

Using the switch-case statement, write a menu driven program to do the following:
    (a) To generate and print Letters from A to Z and their Unicode
                Letters            Unicode
                    A                        65
                    B                        66
                    .                           .
                    .                           .
                    .                           .
                    Z                       90
(b) Display the following pattern using iteration (looping) statement:
                           1
                           1 2
                           1 2 3
                           1 2 3 4
                           1 2 3 4 5
Ans. 

import java.util.*;
class menu
{
   public static void main (String args[])
   {
      Scanner obj = new Scanner (System.in);
      int choice,x;
      System.out.println(" enter 1 for unicode of letters, 2 Pattern");
      choice = obj.nextInt();
      switch(choice)
      {
         case 1: System.out.println(" Letters "+ “ " + " Unicode");
            for (char c='A'; c<='Z'; c++)
            {
               x=c;
               System.out.println( c +" "+ x);
            }
            break;
        case 2:
            for (int i=1; i<=5;i++)
            {
               for (int j=1; j<=i; j++ )
               {
                  System.out.print(j+" ");
               }
               System.out.println();
            }
       } 
   }
}

Question 6. [15 marks]

Write a program to input 15 integer elements in an array and sort them in ascending order using the bubble sort technique.
Ans. 

import java.util.*;
class Bubble
{ 
    public static void main(String[]args)
    {
       Scanner abc = new Scanner (System.in);
       int a[] = new int[15];
       System.out.println("Enter elements");
       for (int i=0;i<15;i++) // OR i< a.length
       {
          a[i]=abc.nextInt();
       }//end of for
       int temp;
       for (int i=0;i<a.length-1;i++) // OR i <14
       {
          for (int j=0;j<(a.length-1)-i;j++) // OR j<14-i
          {
            if(a[j]>a[j+1])
            {
               temp=a[j];
               a[j]=a[j+1];
               a[j+1] =temp;
            }
         }
      }
   }
}

Question 7. [15 marks]

Design a class to overload a function series () as follows:
(a) void series (int x, int n) – To display the sum of the series given below:
         x¹ + x² + x³ + ….x^n terms
(b) void series (int p) – To display the following series:
          0, 7, 26, 63 ……………. p terms
(c) void series ( ) – To display the sum of the series given below:
1/2 + 1/3 + 1/4  . . . 1/10
Ans. 

class Overload
{
    public static void series (int x , int n)
    {
       double sum=0.0;
       for (int i=1;i<=n;i++)
       {
         sum=sum+ Math.pow(x,i);
       }
       System.out.println(sum);
    }
    public static void series (int p)
    {
       for (int i=1; i<=p; i++)
         System.out.println((i*i*i)-1);
    }
    public static void series ()
    {
       double sum=0.0;
       for (int i=2; i<=10;i++)
       {
          sum=sum+(double)1/i;
       }
       System.out.print("Sum= "+sum);
   }//end of function
}

Question 8. [15 marks]

Write a program to input a sentence and convert it into uppercase and count and display the total number of words starting with a letter ‘A’.
Example:
    Sample Input: ADVANCEMENT AND APPLICATION OF INFORMATION TECHNOLOGY ARE EVER CHANGING.
    Sample Output: Total number of words starting with letter ‘A’ = 4.
Ans. 

import java.util.*;
class loop
{
   public static void main (String args[])
   {
      Scanner sc=new Scanner (System.in);
      String str; char ch, ch1; int c=0;
      System.out.println("Enter a sentence");
      str= sc.nextLine();
      str=str.toUpperCase();
      int len= str.length();
      for (int i=0; i<len-1;i++)
      {
         ch= str.charAt(i);
         ch1=str.charAt(i+1);
         if (i==0 && ch=='A')
           c++;
         else if (ch==' ' && ch1=='A')
           c++;
       }
       System.out.println("Number of words started with letter 'A' ="+c);
   }
}

Question 9. [15 marks]

A tech number has even number of digits. If the number is split in two equal halves, then the square of sum of these halves is equal to the number itself. Write a program to generate and print all four digits tech numbers.
Example:
        Consider the number 3025
        Square of sum of the halves of 3025 = (30+25)2
                                                                          = (55)2
                                                                          = 3025 is a tech number.
Ans. 

class Q9
{
   public static void main (String args[])
   {
      int x,i,j,k, n;
      for (x=1000; x<=9999; x++)
      {
         i= x%100;
         j= x/100;
         n= i+j;
         k=n* n;
         if(x== k)
           System.out.println(x);
      }
   }
}