NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 are part of NCERT Solutions for Class 8 Maths. Here we have given NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4.

BoardCBSE
TextbookNCERT
ClassClass 8
SubjectMaths
ChapterChapter 2
Chapter NameLinear Equations in One Variable
ExerciseEx 2.4
Number of Questions Solved10
CategoryNCERT Solutions

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4

Question 1.
Amina thinks of a number and subtracts \(\frac { 5 }{ 2 } \) from it. She multiplies the result by 8. The result now obtained is 3 times the same number she thought of. What is the number?
Solution.
Let the number be x.
Then, according to the question,
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 1

Question 2.
A positive number is 5 times another number. If 21 is added to both the numbers, then one of the new numbers becomes twice the other new number. What are the numbers?
Solution.
Let the numbers be x and 5x.
If 21 is added to both the numbers, then first new number = x + 21
and, second new number = 5x + 21
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 2
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 3

Question 3.
Sum of the digits of a two-digit number is 9. When we interchange the digits, it is found that the resulting new number is greater than the original number by 27. What is the two-digit number?
Solution.
Let the unit’s digit of the two-digit number be x.
Then, the ten’s digit of the two-digit number = 9 – x
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 4
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 5

Question 4.
One of the two digits of a two digit number is three times the other digit. If you interchange the digits of this two-digit number and add the resulting number to the original number, you get 88. What is the original number?
Solution.
Let in the original number
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 6
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 7

Question 5.
Shobo’s mother’s present age is six times Shobo’s present age. Shobo’s age five years from now will be one third of his mother’s present age. What are their present ages?
Solution.
Let the present age of Shobo be x  year. Then, the present age of Shobo’s mother = 6x years.
Five years from now
Shobo’s age = (x + 5) years
According to the question,
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 8
Hence, their present ages are 5 years and 30 years.

Question 6.
There is a narrow rectangular plot, reserved for a school, in Mahuli village. The length and breadth of the plot are in the ratio 11:4. At the rate of ₹ 100 per meter, it will cost the village panchayat ₹ 75000 to fence the plot. What are the dimensions of the plot?
Solution.
Let the length and breadth of the plot be 11x m and 4x m respectively.
Then, the perimeter of the plot
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 9

Question 7.
Hasan buys two kinds of cloth materials for school uniforms, shirt material that costs him ₹ 50 per meter and trouser material that costs him ₹ 90 per meter. For every 2 meters of the trouser material, he buys 3 meters of the shirt material. He sells the materials at 12% and 10% profit respectively. His total sale is ₹ 36,600. How much trouser material did he buy?
Solution.
Suppose that he bought x meters of trouser material.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 10
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 11

Question 8.
Half of a herd of deer are grazing in the field and three fourths of the remaining are playing nearby. The rest 9 are drinking water from the pond. Find the number of deer in the herd.
Solution.
Let the number of deer in the herd be x.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 12

Question 9.
A grandfather is ten times older than his granddaughter. He is also 54 years older than her. Find their present ages.
Solution.
Let the present age of granddaughter be x years
Then, the present age of grandfather is 10x years
According to the question,
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 13

Question 10.
Am.an’s age is three times his son’s age. Ten years ago he was five times his son’s age. Find their present ages.
Solution.
Let the present age of Aman’s son be x years
Then, the present age of Aman
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 14
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 15

 

We hope the NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4 help you. If you have any query regarding NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.4, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 are part of NCERT Solutions for Class 8 Maths. Here we have given NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3.

BoardCBSE
TextbookNCERT
ClassClass 8
SubjectMaths
ChapterChapter 2
Chapter NameLinear Equations in One Variable
ExerciseEx 2.3
Number of Questions Solved1
CategoryNCERT Solutions

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3

Question 1.
Solve the following equations and check your results:
1. 3x=2x+18
2. 5t-3=3t-5
3. 5x+9=5+3x
4. 4z+3=6+2z
5. 2x-1=14-x
6. 8x+4=3(x-1)+7
7. \(x=\frac { 4 }{ 5 } \left( x+10 \right) \)
8. \(\frac { 2x }{ 3 } +1=\frac { 7x }{ 15 } +3\)
9. \(2y+\frac { 5 }{ 3 } =\frac { 26 }{ 3 } -y\)
10. \(3m=5m-\frac { 8 }{ 5 } \)
Solution.
1. 3x=2x+18
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 1

2. 5t-3=3t-5
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 2
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 3

3. 5x+9=5+3x
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 4

4. 4z+3=6+2z
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 6

5. 2x-1=14-x
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 7

6. 8x+4=3(x-1)+7
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 8

7. \(x=\frac { 4 }{ 5 } \left( x+10 \right) \)
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 9

8. \(\frac { 2x }{ 3 } +1=\frac { 7x }{ 15 } +3\)
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 10
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 13

9. \(2y+\frac { 5 }{ 3 } =\frac { 26 }{ 3 } -y\)
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 11

10. \(3m=5m-\frac { 8 }{ 5 } \)
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 12

 

We hope the NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3 help you. If you have any query regarding NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.3, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 are part of NCERT Solutions for Class 8 Maths. Here we have given NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2.

BoardCBSE
TextbookNCERT
ClassClass 8
SubjectMaths
ChapterChapter 2
Chapter NameLinear Equations in One Variable
ExerciseEx 2.2
Number of Questions Solved16
CategoryNCERT Solutions

NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2

Question 1.
If you subtract \(\frac { 1 }{ 2 } \) from a number and multiply the result \(\frac { 1 }{ 2 } \) by you get \(\frac { 1 }{ 8 } \) What is the number ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 1
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 2

Question 2.
The perimeter of a rectangular swimming pool is 154 m. Its length is 2 m more than twice its breadth. What are the length and the breadth of the pool?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 3
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 4

Question 3.
The base of an isosceles triangle is \(\frac { 4 }{ 3 } \)cm. The perimeter of the triangle is \(4\frac { 2 }{ 15 } \)cm. What is the length of either of the remaining equal sides ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 5
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 6

Question 4.
Sum of two numbers is 95. If one exceeds the other by 15, find the numbers.
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 7
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 8

Question 5.
Two numbers are in the ratio 5 :3. If they differ by 18, what are the numbers?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 9

Question 6.
Three consecutive integers add up to 51. What are these integers ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 10

Question 7.
The sum of three consecutive multiples of 8 is 888. Find the multiples.
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 11

Question 8.
Three consecutive integers are such that when they are taken in increasing order and multiplied by 2, 3 and 4 respectively, they add up to 74. Find these numbers.
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 12
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 13

Question 9.
The ages of Rahul and Haroon are in the ratio 5 : 7. Four years later, the sum of their ages will be 56 years. What are their present ages ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 14

Question 10.
The numbers of boys and girls in a class are in the ratio 7 : 5. The number of boys is 8 more than the number of girls. What is the total class strength ?
Solution..
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 25
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 15

Question 11.
Baichung’s father is 26 years younger than Baichung’s grandfather and 29 years older than Baichung. The sum of the ages of all the three is 135 years. What is the age of each one of them ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 16
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 17

Question 12.
Fifteen years from now Ravi’s age will be four times his present age. What is Ravi’s present age ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 18

Question 13.
A rational number is such that when you multiply it by \(\frac { 5 }{ 2 } \) and add \(\frac { 2 }{ 3 } \) to the product, you get\(-\frac { 7 }{ 12 } \). What is the number ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 19
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 20

Question 14.
Lakshmi is a cashier in a bank. She has currency notes of denominations ₹ 100, ₹ 50 and ₹ 10, respectively. The ratio of the number of these notes is 2 : 3 : 5. The total cash with Lakshmi is ₹ 4,00,000. How many notes of each denomination does she have ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 21
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 22

Question 15.
I have a total of oft 300 in coins of denomination ₹ 1, ₹ 2 and ₹ 5. The number of ₹ 2 coins is 3 times the number of ₹ 5 coins. The total number of coins is 160. How many coins of each denomination are with me ?
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 23
Hence, I have 80, 60, and 20 coins of denomination ₹ 1, ₹ 2 and ₹ 5 respectively.

Question 16.
The organizers of an essay competition decide that a winner in the competition gets a prize of ₹ 100 and a participant who does not win gets a prize of ₹ 25. The total prize money distributed is ₹ 3,000. Find the number of winners, if the total number of participants is 63.
Solution.
NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 24

 

We hope the NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2 help you. If you have any query regarding NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Ex 2.2, drop a comment below and we will get back to you at the earliest.

NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2

NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 are part of NCERT Solutions for Class 8 Maths. Here we have given NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2.

BoardCBSE
TextbookNCERT
ClassClass 8
SubjectMaths
ChapterChapter 1
Chapter NameRational Numbers
ExerciseEx 1.2
Number of Questions Solved7
CategoryNCERT Solutions

NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2

Question 1.
Represent these numbers on the number line.
(i) \(\frac { 7 }{ 4 } \)
(ii) \(\frac { -5 }{ 6 } \)
Solution.
(i) \(\frac { 7 }{ 4 } \)
We make 7 markings of distance \(\frac { 1 }{ 4 } \) each on the right of 0 and starting from 0. The seventh marking represents \(\frac { 7 }{ 4 } \)
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 1

(ii) \(\frac { -5 }{ 6 } \)
We make 5 markings of distance \(\frac { 1 }{ 6 } \) each on the right of 0 and starting from 0. The seventh marking represents \(\frac { -5 }{ 6 } \)
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 2

Question 2.
Represent \(\frac { -2 }{ 11 } ,\frac { -5 }{ 11 } ,\frac { -9 }{ 11 } \) on the number line.
Solution.
We make 9 markings of distance \(\frac { 1 }{ 11 } \) each on the left of 0 and starting from 0.
The second marking represents \(-\frac { 2 }{ 11 } \) the fifth marking represents \(-\frac { 5 }{ 11 } \) and the ninth marking represents \(-\frac { 9 }{ 11 } \)
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 3

Question 3.
Write five rational numbers which are smaller than 2.
Solution.
Five rational numbers which are smaller than 2 are 1, \(\frac { 1 }{ 2 } \),0, -1, \(-\frac { 1 }{ 2 } \)

Question 4.
Find ten rational numbers between \(-\frac { 2 }{ 5 } \) and \(\frac { 1 }{ 2 } \)
Solution.
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 4
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 5

Question 5.
Find five rational numbers between:
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 6
Solution.
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 7
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 8
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 9

Question 6.
Write five rational numbers greater than -2.
Solution.
Five rational numbers greater than -2 are:
\(\frac { -3 }{ 2 } \), -1, \(\frac { -1 }{ 2 } \), 0, \(\frac { 1 }{ 2 } \)
There can be many more such rational numbers

Question 7.
Find ten rational numbers between \(\frac { 3 }{ 5 } \) and \(\frac { 3 }{ 4 } \)
Solution.
NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 10

We hope the NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2 help you. If you have any query regarding NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers Ex 1.2, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 12 Informatics Practices Paper 5

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 are part of CBSE Sample Papers for Class 12 Informatics Practices. Here we have given CBSE Sample Papers for Class 12 Informatics Practices Paper 5.

CBSE Sample Papers for Class 12 Informatics Practices Paper 5

BoardCBSE
ClassXII
SubjectInformatics Practices
Sample Paper SetPaper 5
CategoryCBSE Sample Papers

Students who are going to appear for CBSE Class 12 Examinations are advised to practice the CBSE sample papers given here which is designed as per the latest Syllabus and marking scheme, as prescribed by the CBSE, is given here. Paper 5 of Solved CBSE Sample Paper for Class 12 Informatics Practices is given below with free PDF download solutions.

Time : 3 hrs
Maximum Marks : 70

General Instructions

  • All questions are compulsory.
  • Answer the’questions after carefully reading the text.

QUESTIONS

Question 1.
(a) Define a network. What are the different types of networks?
(b) Two neighbourhood schools at a distance of 120 m from each other have decided to join their LkNs using UTP cable, so that they can share their E-Learning resources. But after joining their LANs, they are not able to share the resources due to loss of signal in between. Which device should they use so that signal is amplified in between?
(c) Write the difficulty to sell the software developed using open source software.
(d) What is the mechanism that obtains IP address using a URL of a website?
(e) Define the following terms: (i) Data channel (ii) Baud
(f) Discuss about MODEM. What is its function?
(g) Write down the various facilities provided by the server.

Question 2.
(a) Write HTML code to produce a TextArea with 20 rows and 10 columns.
(b) Identify invalid vanable naines out of the following. State reason if invalid.
(i) switch
(ii) sum 12
(ii) address
(iv) Name
(c) Briefly explain the different GUI output methods used in Java.
(d) Write code for the event handler of a radio button so that when it is selected/unselected, its text changes to “Selected” or “Unselected”.
(e) (i) Rewrite the following program code using if else statement:

int a=jComboBox1.getSelectedlndex ( ) ;
switch(a)
{
case 0 :
GrandTotal=0. 10 * BillAmt ;
break ;
case 1 :
GrandTotal=0 .9 * BillAmt ;
break ;
case 2 :
GrandTotal=O. 8 * Bill Amt ;
break ;
default :
GrandTotal=BillAmt ;

(ii) Neelam has to design two Web pages with following specffications write HTML tags for these :
I. One Web page should have ordered list.
II. Another Web page should have horizontal rule with color ‘Blue’.

Question 3.
(a) How would you display system date as the result of a query?
(b) Following are some statements :

CREATE TABLE EMPLOYEE
(
Emp_Id INT NOT NULL ,
OrderNo INT NOT NULL ,
Emp_rank INT ,
PRIMARY KEY(Emp_Id) ,
FOREIGN KEY(Emp_rank) REFERENCES Persons(Emp_rank)
) ;

Identify the number and types of constraints in the above table EMPLOYEE.

(c) Ahuja entered the following SQL statement to display all workers of the country “US” and “India” from the table “PROFIT”.
CBSE Sample Papers for Class 12 Informatics Practices Paper 5 1

SELECT*FROM PROFIT WHERE Country='US' AND Country-'India' ;

Rewrite the correct statement, if it is wrong.

(d) Consider the table :
CBSE Sample Papers for Class 12 Informatics Practices Paper 5 2
(i) Write query to display Emp_Name, Emp_Salary whose name starts from ‘S’.
(ii) Delete the record of employee Neeru from the table COMPANY.

(e) (i) Consider the CUSTOMER table.
CBSE Sample Papers for Class 12 Informatics Practices Paper 5 3

The following SQL queries are executed on the above table :

INSERT INTO CUSTOMER VALUES ('C106', ‘Aakash’) ;
COMMIT ;
UPDATE CUSTOMER SET Cust_Name='Abhishek' WHERE Cust_ID='C104'; SAVEPOINT P ;
INSERT INTO CUSTOMER VALUES ('C107','Chris') ;
SAVEPOINT Q ;
INSERT INTO CUSTOMER VALUES ('C108Gagan’) ;
SAVEPOINT R ;
ROLLBACK TO Q ;

What will be the output of the following SQL query now?

SELECT*FROM CUSTOMER ;

(ii) An attribute P of datatype VARCHAR (30) has the value “Rastogi”. The attribute Q of datatype CHAR(30) has value “Garg”. How many characters are occupied in attributes P and Q?

Question 4.
(a) What will be the value of variables’m’ and ‘n’ after the execution of the following code?

int m,n = 0 ;
for(m = 1; m <= 4; m++)
{
n+=m;
n- -;
}

(b) (i) Write the corresponding Java expressions for the following mathematical expressions :

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 5

(c) (i) What is XML editor? Also, write Free XML editors.
(ii) The following code has some error(s). Rewrite the correct code underlining all the correction made.

float m=6, float n=1,p=1 ;
do ;
{
p==p*n ;
n++ ;
while (n<=m)
j TextFieldl.setText (" " +p) ;
}

(d) Read the following case study and answer the questions that follow :

Mr. Das is working as a Chief Information Officer in AMD constructions company. In the month of January, he received a letter from the management to store all his employees information in electronic form. He decided to develop a small software application form to store employee’s personal data. He instructed one of his juniors to make a form in Java swing to enter employees information. The junior presented the following form to Mr. Das.

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 6

The form details are given in the following table :

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 7

(i) Write a code snippet on Action Event of ClearFormBTN button to clear Text Field objects, set default choice in the Radio Buttons to Female and clearing all CheckBox controls.
(ii) Write a method ProCheckQualification to be called in the Submit Button’s Action Event. The procedure code will perform the following action:

If the Check Box PostGraduateCB is checked, then the procedure will automatically check the CheckBoxes GraduatcCB and lntermediateCB irrespective of their initial state. Similarly, if the CheckBox GraduateCB is checked then automatically check IntermethateCB, otherwise only IntermediateCB should be automatically checked.

(iii) Write a method ProConvertCase to convert all the employee details in NameTF, FatherNameTF, MotherNameTF and AddressTF to upper case characters.

Question 5.
(a) How do you select all rows from a table named “PRODUCT’ where the value of the column “Product_name” starts with “B”?
(b) What is null value in MySQL database?
(c) (i) Riya Pandey is the Manager of company named Royal, she wants to create a table ‘EMPLOYEE’ to store details of her company.

I. Which of the following can be the attribute(s) of ‘EMPLOYEE’ table?
i. EmpNo
ii. ”Rahul”
iii. Name
iv. 115

II. Name the primary key of the table ‘EMPLOYEE’. State reason for choosing it.

(ii) Write the output of the following SQL queries :

I. SELECT TRUNCATED.864,2) ;
II. SELECT RIGHT(CONCAT(’PUBLICATION', 'ARIHANT'), 4) ;

(d) Consider the following table named “BANK” with details of account holders.
Write commands in SQL for (i) and (ii) and outputs for (iii) and (iv).

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 9

(i) To display all information of account holders whose transaction value is not mentioned.
(ii) To add another column Address with datatype VARCHAR and size (30).

(iii) SELECT Name, Balance FROM BANK WHERE Name LIKE '%i%' ;
(iv) SELECT ROUNDCBalance, -3) FROM BANK WHERE AccountNo = ’B2436’ ;

Question 6.
(a) (i) Write a MySQL command for creating a table ‘SUPPLIERS’

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 12
(ii) In a database Bank, there are two tables CUSTOMER and TRANSACTION with the following contents :

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 13
I. The Cust_ID column in the CUSTOMER table is the key.
The Cust_ID column in the TRANSACTION table is a key.

II. Identify the attributes, which can be chosen as candidate keys in the table CUSTOMER. Also, define candidate key.
(b) With reference to the above given tables (in Q.6 (a) (ii)), write SQL commands for (i) and (ii) and output for (iii).

(i) To add a column Tranjfype with datatype VARCHAR and size 15 in the table TRANSACTION.
(ii) To display Cust_ID, Cust_Name, Account_No, Tran lD, Amount where Amount is greater than 5000.00

(iii) SELECT Cust_ID, Cust_Name, Tran_ID, Amount 
FROM CUSTOMER, TRANSACTION
WHERE CUSTOMER.Cust_ID = TRANSACTION.Cust_ID
AND Account_Type = "Saving" ;

Question 7.
(a) Define front-end of an information system.
(b) E-Business is useful for both businessmen and customer. What benefits does an E-Business offer to the customer?
(c) Muskan works for a store. She wants to create controls on a form for the following functions. Which controls should she use? Choose appropriate controls from TextBox, Label, OptionButton, CheckBox, IistBox, ComboBox, CommandButton.

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 15

ANSWERS

Answer 1.
(a) A network is an interconnected collection of autonomous computers and devices via same kind of transmission machine. Networks can be classified into three categories which are as follows:

  1. Local Area Network (LAN)
  2. Metropolitan Area Network (MAN)
  3. Wide Area Network (WAN)

(b) Repeater is a device used to amplify signals.

(c) Sometimes there is no commercial market for software. You cannot sell software using previous trademarks, which is developed by another person.

(d) Domain Name Resolution.

(e) (i) A data channel is the medium used to carry information or data from one point to another.
(ii) Baud is the unit of measurement for the information carrying capacity of a communicatton channel of analog type. It is synonymous with bps (bits per second) of digital type circuit.

(f) A modem is a computer peripheral device that connects a workstation to other workstations via telephone lines and facilitates communications. It is short form for MOdulation/DEModulation. Modem converts digital signals into analog signals and vice-versa.

(g) Facilities provided by the server in a network environment are as follows:

  1. Resource sharing
  2. Centralised database storage
  3. Internet sharing with authentication
  4. Account monitoring

Answer 2.

(a) <TEXTAREA rows= "20" cols= “10” name= "tar” > Enter detail</TEXTAREA>

(b) (i) switch is invalid because variable names must not be a keyword.
(c) For displaying an output in a Java program, we can use either of the two methods. which are as foIlows:

System.ouiprint ( ) This method displays the text and keeps the cursor in the same line.
System.out.printin ( ) This method displays the text and then moves the cursor to the next line.

(d) private void RdBtnStateChanged ( javax.swing.event.ChangeEvent evt )
{
//RdBtn is the name of Radio Button
if ( RdBtn.isSelected ( ) )
RdBtn.setText ("Selected") ;
else
RdBtn.setText ("Unselected") ;
}

(e) (i) The rewritten code with the use of if else Statement is as follows :
int a=j ComboBox1.getSelectedlndex( ) ;
if (a==0)
GrandTotal=0.10*Bill Amt :
else if(a==1) .
GrandTotal=0.9*BllAmt ;
else if(a==2)
GrandTotal=0.8*BillAmt;
else
GrandTotal=BillAmt ;
(ii) I. <0L> <LI>
II. <HR color='blue'>

Answer 3.
(a) To obtain current system date :

SELECT CURDATE ( ) ;

(b) There are three constraints defined in EMPLOYEE table, are as follows :
(i) Two NOT NULL constraints for column Empjd and OrderNo.
(ii) One PRIMARY KEY constraint for column Empjd.
(iii) One FOREIGN KEY constraint for column Emp_rank.

(c) The correct code is,

SELECT*FROM PROFIT WHERE Country='US' OR Country-'India' ;

(d)

(i) SELECT Emp_Name, Emp_Salary FROM COMPANY WHERE Emp_Name LIKE'S%' ;
(ii) DELETE FROM COMPANY WHERE Emp_Name='Neeru' ;

(ii) The number of characters occupied in attribute P has value Rastogi are 7 and in attribute Q has value Garg are 4.

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 4

Answer 4.
(a) Value of m 5 and n = 5

(b) (i) I. float A = (((b + f) / c ) - d) ; 
II. float z = x * x * x + y * y - (sqrt(x*y))/2 ;

(ii) Java code is ;
float price=Float.parseFloat ( j TextField1.getText ( ) ) ;
int quantity=Integer.parselnt ( j TextFleld2.getjext ( ) ) ;
float tot=price*quantity ;
float tax=tot*10/100 ;
j TextFleld3.setText(” “+tot) ;
j TextField4.setText(” “+tax) ;

(c)
(i) XML editor allow you to create and manipulate XML documents. The basic features which you need are syntax highlighting, color code to make XML easier to read and understand.

Free XML editors

  1. XML look top
  2. XML mind standard Edition
  3. Peter’s XML editors

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 8

(d) (i) private void ClearFormBTNActionPerformed(javax.swing.event.ActionEvent evt)
{
NameTF.setText (" ") ;
FatherNameTF.setText (" ") ;
MotherNameTF.setText (" ") ;
AddressTF.setText (" ") ;
FemaleRB.setSelected(true) ;
IntermediateCB.setSelected(false) ;
GraduateCB.setSelected(false);
PostGraduateCB;setSelected(false) ;
}
(ii) void ProCheckQual ification ( )
{
if (PostGraduateCB.isSelected ( ) )
{
GraduateCB.setSelected(true) ;
IntermediateCB.setSelected(true) ;
}
else if (GraduateCB.isSelected ( ) )
{
IntermediateCB.setSelected(true) ;
}
else
IntermediateCB.setSelected(true) ;
}
(iii) void ProConvertCase ( )
{
String Name = NameTF.getText ( ) ;

NameTF.setText(Name.tollpperCase( ) ) ;
String Fname = FatherNameTF.getText( ) ;
FatherNameTF.setText(Fname.toUpperCase( ) ) ;
String Mname = MotherNameTF.getText( ) ;
MotherNampTF.setText(Mname.tollpperCase( ) ) ;
String add = AddressTF.getText( ) ;
AddressTF.setText(add.toUpperCase( ) ) ;
}

Answer 5.

(a) SELECT* FROM PRODUCT WHERE Product_name LIKE ’B%’ ;

(b) If a column in a row has no value, then column is said to be null, or to contain a null.
(c) (i) I. i. EmpNo ii. Name

II. Primary key is EmpNo as it will be unique for each employee of the company.
(ii) Output of the above queries :

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 10

(d) (i) SELECT * FROM BANK WHERE Transaction IS NULL ;
(ii) ALTER TABLE BANK ADD Address VARCHAR(30) ;
CBSE Sample Papers for Class 12 Informatics Practices Paper 5 11

Answer 6.

(a) (i) CREATE TABLE SUPPLIERS
(
Product_id INT(4),
Product_Name CHAR(10),
Quantity I NT (10),
Price DECIMAL (7,2),
Phone CHAR (10)
) ;

(ii) I. Primary, Foreign
II. Candidate keys: Cust_ID, Account_No

A candidate key can be defined as a column or set of columns, in a table that can uniquely identify any database record without referring to any other data.

(b) (i) ALTER TABLE TRANSACTION ADD Tran_Type VARCHAR (15) ;
(ii) SELECT Cust_ID, Cust_Name, Account_No, Tran_ID, Amount
FROM CUSTOMER. TRANSACTION
WHERE CUSTOMER.Cust_ID=TRANSACTION.Cust_ID AND Amount>5000.00 ;
CBSE Sample Papers for Class 12 Informatics Practices Paper 5 14

Answer 7.
(a) Front-end of an information system This is the user interface that the users see and which is responsible for interacting with the user. The front-end is responsible for receiving user’s queries, requests etc., and passing it over to the back-end.

(b) E-Business offers following benefits to the customers :

  1. Improved speed of response
  2. Cost savings
  3. Improved efficiency and productivity
  4. Improved customer service.

CBSE Sample Papers for Class 12 Informatics Practices Paper 5 16

We hope the CBSE Sample Papers for Class 12 Informatics Practices Paper 5 help you. If you have any query regarding CBSE Sample Papers for Class 12 Informatics Practices Paper 5, drop a comment below and we will get back to you at the earliest.