NCERT solutions for class 7 maths chapter 3 Data Handling In everyday life people deal with various types of data. The chapter data handling discusses how to represent and organize data in different ways so that their interpretation and analysis become easier. The solutions of NCERT class 7 maths chapter 3 data handling contains 4 exercises with 23 questions. Also along with these, there is an explanation to topic wise questions in the CBSE NCERT solutions for class 7 maths chapter 3 data handling. Collection of data and representing it using a bar graph are dealt with in class 6. More types of data and graphs are dealt with in class 7 chapter 3 data handling. Certain examples of data are temperatures of cities on a particular day, weekly absentees in a class, etc. and some basic terms like arithmetic mean, range, mode, and median are discussed. Questions on these topics are explained in the NCERT solutions for class 7 maths chapter 3 data handling. To perform well in the exam the NCERT solutions are helpful.
3.1 Introduction
3.2 Collecting Data
3.3 Organisation of Data
3.4 Representative Values
3.5 Arithmetic Mean
3.5.1 Range
3.6 Mode
3.6.1 Mode of Large Data
3.7 Median
3.8 Use of Bar Graphs withe a Different Purpose
3.8.1 Choosing a Scale
3.9 Chance and Probability
3.9.1 Chance
Q. Find at least 5 numbers between 1/2 and 1/3
Given number are: and
Their average =
Average between =
Average between =
Average between =
Average between =
Therefore, 5 numbers between and are:
(i) 2, 6, 5, 3, 0, 3, 4, 3, 2, 4, 5, 2, 4
(ii) 2, 14, 16, 12, 14, 14, 16, 14, 10, 14, 18, 14
(i) Given,
2, 6, 5, 3, 0, 3, 4, 3, 2, 4, 5, 2, 4
Arranging in ascending order:
Here, 2, 3 and 4 all occur three times. Therefore, all three are modes of data.
(ii) Arranging in ascending order:
Here, occurs 6 times. Therefore, is the mode of the data.
Find the mode of 2, 14, 16, 12, 14, 14, 16, 14, 10, 14, 18, 14
Arranging in ascending order:
Here, occurs 6 times. Therefore, is the mode of the data.
Data  Tally bars  Number of times 
12  3  
13  4  
14  5  
15  10  
16  6  
18  1  
19  1 
Clearly, 15 occurs 10 times. Therefore, 15 is the mode of the data.
Solutions for NCERT class 7 maths chapter 3 data handling topic 3.8.1
2 a) Sale of English and Hindi books in the years 1995, 1996, 1997 and 1998 are given below:
Draw a double bar graph and answer the following questions:
(a) In which year was the difference in the sale of the two language books least?.
In 1998, the difference in the sale of the two language books was the least
Q Sale of English and Hindi books in the years 1995, 1996, 1997 and 1998 are given below:
Draw a double bar graph and answer the following questions:
(b) Can you say that the demand for English books rose faster? Justify.
Numbers  Frequency 
1  1 
2  2 
3  1 
4  3 
5  5 
6  4 
7  2 
8  1 
9  1 
(i) is the highest number.
(ii) is the lowest number
(iii) Range of the data = Highest number  Lowest number
(iv) Arithmetic mean =
Therefore, the mean of the data is
3. Find the mean of the first five whole numbers.
The first five whole numbers are
We know, Arithmetic mean
Therefore, the mean of the first five whole numbers is
Given,
Runs scored in eight innings =
We know, Arithmetic mean
Therefore, the mean score is
Given,
We know,
(i) Therefore, A's average number of points scored per game
(ii) Number of games C played = 3
Therefore, to find the mean, we will divide by 3
Mean of C =
(iii) Although he scored 0 in a match, he played all 4 games. Therefore, we will divide by 4.
Mean of B =
(iv) Mean of A =
Mean of B =
Mean of C =
Since, A has the highest mean, A is the best performer.
Given,
Marks obtained the students =
Arranging in ascending order =
(i) Highest marks obtained =
Lowest marks obtained =
(ii) Range of marks = Highest marks  Lowest marks
(iii) We know, Arithmetic mean
Therefore, mean marks =
Given,
Enrolment during 6 consecutive years =
We know, Arithmetic mean
Therefore, the mean enrolment per year is
Given,
(i) Range = Maximum rainfall  Minimum rainfall
(ii) We know, Arithmetic mean =
Therefore, mean rainfall is
(iii) Here, mean =
Mon(0.0), Wed(2.1), Thu(0.0), Sat(5.5), Sun(1.0) are less than the mean
Therefore, on 5 days, rainfall was less than the mean.
Given,
Heights of 10 girls (in cm) =
Arranging the above data in ascending order =
(i) Height of the tallest girl =
(ii) Height of the shortest girl =
(iii) Range of the data =
(iv) We know, Arithmetic mean =
Therefore, the mean height of the girls is
(iv) Here, mean height =
And, are more than
Therefore, 5 girls have a height more than the average height.
Scores of 15 students are :
Arranging the data in ascending order =
We know,
Mode: The number which occurs most frequently.
Median: Median is the midvalue of the set of numbers.
Here, 20 occurs 4 times, therefore 20 is the mode of the data.
Also, the middle value is 20.
Therefore, the median of the data is 20.
Yes, the median and mode of this data are the same.
Runs scored in the match =
Arranging in ascending order =
Here, 15 occurs the maximum number of times. Hence, 15 is the mode of the data
Now,
Therefore the mean score is
Now, the median is the middle observation of the data.
There are 11 terms. Therefore the middle observation is
Therefore, 15 is the median of the data.
No, they are not the same.
Given, weights of 15 students (in kg)=
Arranging the data in ascending order =
(i) Clearly, 38 and 43 both occur thrice. So, they both are the mode of the data.
Now, there are 15 values, so the median is the
Hence, 40 is the median value.
(ii) Yes, there are two modes of the data given.
4. Find the mode and median of the data: 13, 16, 12, 14, 19, 12, 14, 13, 14
Given,
Arranging in ascending order =
We know,
The mode is the observation which occurs a maximum number of times.
Median is the middle observation when that data is arranged in ascending or descending order.
Now,
Clearly, occurs thrice. So, is the mode of the data.
Now, there are 9 values, so the median is the
Hence, is the median value.
(i) True.
The mode is the observation which occurs maximum number of times.
Hence, the mode will always be one of the numbers in data.
(ii) False.
(iii) False.
For even number of observations, the median is the mean of the and values.
(iv) Mean =
Hence, the statement is false.
(a)
The bar graph represents the pets owned by the students of class seven.
And, The bar of the cat is the tallest
Hence, the cat is the most popular pet.
(b)
The bar of the dog reaches the value 8
8 students have dog as pet.
(i) Observing the graph,
Number of books sold in 1989 = 180
Number of books sold in 1992 = 220
Number of books sold in 1990 = 480
(ii)
475 books were sold in the year 1990
225 books were sold in the year 1992
(iii)
The years in which the total number of books sold was less than 250 are 1989 and 1992.
(iv) Around 175 books were sold in the year 1989.
By drawing a line from the top of 1989 bar to the yaxis.
(a) The scale : 1 unit = 10 children.
(b) (i) Class fifth has the maximum number of children.
Whereas, class tenth has the minimum number of children
(ii) Number of students in class sixth = 120
Number of students in class eight = 100
Therefore, the required ratio =
Required ratio is
(i) According to the graph, Maths had the maximum increase in marks.
Hence,
The child improved his performance the most in Maths.
(ii) According to the graph, S.Science had the least increase in marks.
Hence,
The child improved his performance the least in S.Science.
(iii) According to the graph, Hindi's marks went down in the second term
Hence,
The child’s performance has gone down in Hindi.
(i)
The double bar graph represents the number of people who like watching and participating in various sports.
We observe that,
The maximum number of people like either watching or participating in cricket.
The minimum number of people like either watching or participating in athletics.
(ii) According to the graph, the tallest bar is of cricket. Hence, cricket is the most popular sport.
(iii) The bars corresponding to watching sports are longer than the bars corresponding to participating in sports.
Hence, watching sports is preferred over participating in sports.
Table 3.1 is
The double bar graph is :
(i) From the graph,
Jammu has the largest difference between the maximum and minimum temperature bars.
Jammu is the city with the largest difference in its maximum temperature and minimum temperatures on the given date.
(ii) The city with the maximum temperature would be the hottest.
And the city with the least temperature will be the coolest.
According to the graph, Jammu has the highest maximum temperature bar.
Jammu is the hottest city.
Also, the lowest minimum temperature bar is of Bangalore.
Bangalore is the coolest city.
(iii) Maximum temperature of Bangalore is
The minimum temperature of Jaipur is
The required pair of two cities are: Bangalore and Jaipur
(iv) Mumbai is a city with the least difference in its maximum temperature and minimum temperatures.
(i) You are older today than yesterday.
This event is certain to happen.
(ii) A tossed coin will land heads up.
 This event can happen but not certain.
(iii) A die when tossed shall land up with 8 on top.
 This event is impossible. A die can only show one of the numbers (1,2,3,4,5,6)
(iv) The next traffic light seen will be green.
 This event can happen but not certain.
(v) Tomorrow will be a cloudy day.
 This event can happen but not certain.
There are 6 marbles in the box numbered from 1 to 6
(i) Number of marble with number 2 on it = 1
Probability of getting a marble with number 2
(ii) Number of marble with number 5 on it = 1
Probability of getting a marble with number 5
We know, a coin has two faces: Head and Tail
One can choose either Head or Tail.
Therefore, the number of favourable outcome = 1
We know, Probability of any outcome
Chapter No. 
Chapter Name 
Chapter 1 

Chapter 2 
CBSE NCERT solutions for class 7 maths chapter 2 Fractions and Decimals 
Chapter 3 
NCERT solutions for class 7 maths chapter 3 Data Handling 
Chapter 4 
Solutions of NCERT for class 7 maths chapter 4 Simple Equations 
Chapter 5 
CBSE NCERT solutions for class 7 maths chapter 5 Lines and Angles 
Chapter 6 
NCERT solutions for class 7 maths chapter 6 The Triangle and its Properties 
Chapter 7 
Solutions of NCERT for class 7 maths chapter 7 Congruence of Triangles 
Chapter 8  NCERT solutions for class 7 maths chapter 8 comparing quantities 
Chapter 9 
CBSE NCERT solutions for class 7 maths chapter 9 Rational Numbers 
Chapter 10 
NCERT solutions for class 7 maths chapter 10 Practical Geometry 
Chapter 11 
Solutions of NCERT for class 7 maths chapter 11 Perimeter and Area 
Chapter 12 
CBSE NCERT solutions for class 7 maths chapter 12 Algebraic Expressions 
Chapter 13 
NCERT solutions for class 7 maths chapter 13 Exponents and Powers 
Chapter 14 
Following are the basic terms delt in the chapter. These terms are important and are used in the NCERT solutions for class 7 maths chapter 3 data handling. Also in higher classes, these terms are studied in detail.
7. The enrolment in a school during six consecutive years was as follows:
1555, 1670, 1750, 2013, 2540, 2820
Find the mean enrolment of the school for this period.
1. Use the bar graph (Fig 3.3) to answer the following questions.
(a) Which is the most popular pet? (b) How many students have dog as a pet?
5. Tell whether the statement is true or false:
(i) The mode is always one of the numbers in a data.
(ii) The mean is one of the numbers in a data.
(iii) The median is always one of the numbers in a data.
(iv) The data 6, 4, 3, 8, 9, 12, 13, 9 has mean 9.