Friday, December 2, 2016

CBSE Class 8 Maths - Linear Equations In One Variable (Q and A)

Linear Equations In One Variable

Class 8

Q & A based on Class 8 NCERT Chapter 

CBSE Class 8 Maths - Linear Equations In One Variable (Q and A)


Q1(MCQ): If 3x – 4 (64 – x) = 10, then the value of x is

(a) –266
(b) 133
(c) 66.5
(d) 38



Answer: (d)38
  3x - 256 + 4x =10
  7x = 10 + 256 = 266
  x = 266/7 = 38


Q2: Three consecutive even numbers whose sum is 156 are 51, 52 and 53.
State if the above statement is True or False

Answer: False

Let the three consecutive even numbers be x, x+2, x+4
∴ x + x+ 2 + x+4 = 156
⇒ 3x + 6 = 156
⇒ 3x = 156 - 6 = 150
⇒ x = 150 /  3 = 50
Thus numbers are 50, 51, 52


Q3: Fifteen added to thrice a whole number gives 93. The number is __________.

Answer: 26



Q4: x = –12 is the solution of the linear equation 5x –3(2x + 1) = 21+x (True or False)


Thursday, December 1, 2016

CBSE Class 9 - Maths - Quadrilaterals (Questions and Answers)

Quadrilaterals 

CBSE Class 9 - Maths - Quadrilaterals (Questions and Answers)


Class 9 NCERT Exemplar Problems and Solutions

Question 1: If angles A,B,C and D of a quadrilateral ABCD, taken in order, are in the ratio 3:7:6:4 then ABCD is a trapezium. Is this statement true? Give reason for your answer.

Solution: Since, the angles are in the ratio 3:7:6:4,

Let these angles be 3x,7x,6x and 4x.

∵Since sum of angles of a quadrilateral is 360°,

∴3x+7x+6x+4x=360°

⇒ 20x=360°

⇒x=18°

∴The angles are:
   ∠A=3×18°=54°,
  ∠B=7×18°=126°,
  ∠C=6×18°=108° and
 ∠D=4×18°=72°

Since ∠A+∠B=54°+126°=180°. Thus, the sum of co-interior angles is 180°formed by lines AD,BC and transversal AB, ∴, AD∥BC.

So,ABCD is a trapezium.

Hence, the given statement is true.

CBSE Class 6-10 - English Grammar - Error Correction - Subject-Verb Agreement

Error Correction - Subject-Verb Agreement

English Grammar


CBSE Class 6-10 - English Grammar - Error Correction - Subject-Verb Agreement


The verb in a sentence has to agree with the number of the subject.

Rule 1: A singular subject takes a singular verb.
e.g.

A girl _______ (dance/dances) beautifully.  [Answer: dances]

This article _________ (has/have) three paragraphs.  [Answer: has]


Rule 2: A plural subject takes a plural verb.

e.g.

Those girls __________ (dance/dances) beautifully.   [Answer: dance]

These articles _________ (has/have) single paragraph only.  [Answer: have]


Rule 3: If two singular nouns are joined by 'and' and used as the subject, it takes plural verb.

e.g.
Mohan and Sudama  _________ (was/were) fast friends.   [Answer: were]

He and I _________(am/are) going to welcome them. [Answer: are]


Exceptions: Words used in pairs like 'bread and butter', 'bag and baggage' are considered singular and take singular verbs.

e.g. Blogging ______ (is/are) my bread and butter now.


Wednesday, November 30, 2016

CBSE Class 7 - Social and Political Life II - Chapter 7 - Understanding Advertising (Questions and Answers)

Social and Political Life II  
Chapter 7 

Understanding Advertising


Questions & Answers based on NCERT Chapter 7 Class 7

CBSE Class 7 - Social and Political Life II - Chapter 7 - Understanding Advertising (Questions and Answers)


Q1: Define advertisement.

Answer: Advertising is any paid form of presentation and promotion of ideas, products and services by an identified sponsor.


Q2: What is product?

Answer: A product refers to a thing or good or service that has been made for being sold in the market.


Q3: What do you understand by the word brand? List two reasons why building brands is central to advertising?

Answer: A brand means stamping a product with a particular name or symbol or sign by which it is differentiated from other products in the market.

Two reasons why building brand is central to advertising are:

① It builds a positive image about the product and thus helps consumer to buy it.
② It differentiates the product from other competitive products available in the market.

Saturday, November 26, 2016

Class 6 - Civics - Chapter 3 - What is Government?

What is Government?

Class 6 - Civics - Chapter 3 - What is Government?

Class 6 Civics NCERT Chapter Solutions and Q & A


Question 1: What do you understand by the world 'government'? List five ways in which you think the government affects your daily life?

Answer: The government affects our daily lives in the following ways:

① It protects boundaries of the country and maintains peaceful relations with other countries.

② It ensures that there is no food shortage and every citizen gets food to eat.

③ It provides health care facilities to look after the health of the people.

④ In case of natural disasters like Tsunami or an earthquake or emergencies, the government organises aid and assistance for the affected people.

⑤ If there is a dispute or crime, the courts will provide justice.

⑥ It helps in building country's infrastructure e.g. Bharat petroleum, Indian Railways are the institutions run by the government.



Question 2: Why do you think the government needs to make rules for everyone in the from laws?

Answer: It is necessary for the government to make rules for everyone in the from laws because:

It helps in proper functioning of the government.

It fulfills the assurances set by our constitution i.e. Justice, Liberty, Equality and Fraternity.

It ensures there is crime free society and all citizens lead to peacful life.

It prevents authority misusing the powers.



Question 3: Name the essential features of a democratic government?

Answer: The essential features of a democratic government are:

① In democracy, it is the people who give the government this power. Citizens  participate to form a government by election process.

② The government is answerable to the people for its actions and decisions.


Friday, November 25, 2016

CBSE Class 9 - Science - Floatation 7 Simple Numerical You Must Know

Floatation
7 Simple Numerical You Must Know

CBSE Class 9 - Floatation - 7 Simple Numerical You Must Know


Q1: A force of 200 N acts on a surface of area 10 cm2. Calculate thrust and pressure. How much the pressure changes if the area of contact increases to 50 cm2.

Answer:
Force = 200 N
Area = 10cm2 = 10 x 10-4m2
Pressure (P) = Force ÷ Area
P1 = 200 ÷ 10 x 10-4 = 2 x 105 Pa

New area = 50cm2 = 50 x 10-4m2
P2 = 200 ÷ 50 x 10-4 = 4 x 104 Pa

Change in Pressure = P1 - P2 = 2 x 105   - 4 x 104
                                = 1.6 x 105 Pa



Q2: A cuboid room has dimensions 50m x 15m x 3.5m. What is the mass of the air enclosed in the room if the density of air = 1.30 kg/m3.


Answer: Volume of room (V) = 50m x 15m x 3.5m = 2625m3
Density of air (d) = 1.30 kg/m3
Mass of air = V x d = 2625 x 1.30 = 3412.5 kg



Sunday, November 20, 2016

Class 10 - Biology - How Do Organisms Reproduce? - Worksheet

Reproduction 


Longitudinal Section of a Bisexual Flower
Label the parts of the flowers (answer given in this post)
image credits: wikimedia

Worksheet


Fill in the blanks


1. In _________, many bacteria and protozoa simply divide into two or more daughter cells.


2. __________ is associated with the stability of population of species.


3. The fertilized egg gets implanted in the lining of the ________.


4. In mammals, the embryo gets nutrition from the mother’s blood with the help of a special tissue called _________.