RS Aggarwal 2019,2020 solution class 7 chapter 22 Bar Graphs Exercise 22

Exercise 22

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Question 1:

The marks of a student in different subjects are given below:
 

Subject	Hindi	English	Maths	Science	Social science
Marks	43	56	80	65	50

Draw a bar graph from the above information.

Answer 1:

We can draw the bar graph by following the given steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the names of the subjects at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 10 marks
1 small division = 1 mark

Step 4.- Heights of the various bars are:
   Hindi = 43 small divisions = 4 big divisions and 3 small divisions
   English = 56 small divisions = 5 big divisions and 6 small divisions
   Maths = 80 small divisions = 8 big divisions
   Science = 65 small divisions = 6 big divisions and 5 small divisions
   Social Science = 50 small divisions = 5 big divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

Question 2:

The following table shows the favourite sports of 250 students of a school.
Represent the data by a bar graph.
 

Sports	Cricket	Football	Tennis	Badminton	Swimming
No. of students	75	35	50	25	65

Answer 2:

We can draw the bar graph by following the given steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the names of the sports at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 10 students
1 small division = 1 student

Step 4.- Heights of the various bars:
   Cricket = 75 small divisions = 7 big divisions and 5 small divisions
   Football = 35 small divisions = 3 big divisions and 5 small divisions
   Tennis = 50 small divisions = 5 big divisions
   Badminton = 25 small divisions = 2 big divisions and 5 small divisions
   Swimming = 65 small divisions = 6 big divisions and 5 small divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

Question 3:

Given below is a table which shows the year wise strength of a school. Represent this data by a bar graph.
 

Year	2011-12	2012-13	2013-14	2014-15	2015-16
No. of students	800	975	1100	1400	1625

Answer 3:

We can draw the bar graph by following the given steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the years at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 100 students
1 small division = 10 student

Step 4.- Heights of the various bars:
    2011-2012 = 80 small divisions = 8 big divisions
    2012-2013 = 97.5 small divisions = 9 big divisions and 7.5 small divisions
    2013-2014 = 110 small divisions = 11 big divisions
    2014-2015 = 140 small divisions = 14 big divisions
    2015-2016 = 162.5 small divisions = 16 big divisions and 2.5 small divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 4:

The following table shows the number of scooters produced by a company during six consecutive years. Draw a bar graph to represent this data.
 

Year	2011	2012	2013	2014	2015	2016
No. of scooters	11000	14000	12500	17500	15000	24000

Answer 4:

We can draw the bar graph by following the given steps:-
Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the years at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 2000 scooters
1 small division = 200 scooters

Step 4.- Heights of the various bars:
    2011 = 55 small divisions = 5 big divisions and 5 small divisions
    2012 = 70 small divisions = 7 big divisions
    2013 = 62.5 small divisions = 6 big divisions 2.5 small divisions
    2014 = 87.5 small divisions = 8 big divisions and 7.5 small divisions
    2015 = 75 small divisions = 7 big divisions and 5 small divisions
    2016 = 120 small divisions = 12 big divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

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Question 5:

The birth rate per thousand in five countries over a period of time is shown below:
 

Country	China	India	Germany	UK	Sweden
Birth rate per thousand	42	35	14	28	21

Represent the above data by a bar graph.

Answer 5:

We can draw the bar graph by following the given steps:
Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the names of the countries at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 5 unit
2 small division = 1 unit

Step 4.- Heights of the various bars:
   China = 84 small divisions = 8 big divisions and 4 small divisions
   India = 70 small divisions = 7 big divisions
   Germany = 28 small divisions = 2 big divisions and 8 small divisions
   U.K. = 56 small divisions = 5 big divisions and 6 small divisions
   Sweden = 42 small divisions = 4 big divisions and 2 small divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 6:

The following data shows India's total population (in millions) from 1961 to 2011.
 

Year	1961	1971	1981	1991	2001	2011
Population (in millions)	360	420	540	680	1020	1200

Answer 6:

The graph obtained is as follows:

Question 7:

The following table shows the interest paid by India (in thousand crore rupees) on external debts during the period 1998-99 to 2002-03. Represent the data by a bar graph.

Year	1998-99	1999-2000	2000-01	2001-02	2002-03
Interest (in thousand crore rupees)	70	84	98	106	120

Answer 7:

We can draw the bar graph by following the given steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the years at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 10 thousand crore rupees
1 small division = 1 thousand crore rupees

Step 4.- Heights of the various bars:
    1998−99 = 70 small divisions = 7 big divisions
    1999−2000 = 84 small divisions = 8 big divisions and 4 small divisions
    2000−2001 = 98 small divisions = 9 big divisions and 8 small divisions
    2001−2002 = 106 small divisions = 10 big divisions and 6 small divisions
    2002−2003 = 120 small divisions = 12 big divisions
Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.
We get the following bar graph:
 

Question 8:

The air distances of four cities from Delhi (in km) are given below:

City	Kolkata	Mumbai	Chennai	Hyderabad
Distance from Delhi (in km)	1340	1100	1700	1220

Draw a bar graph to represent the above data.

Answer 8:

We can draw the bar graph by following steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the names of the cities at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 100 km
1 small division = 10 km

Step 4.- Heights of the various bars:
    Kolkata = 134 small divisions = 13 big divisions and 4 small divisions
    Mumbai = 110 small divisions = 11 big divisions
    Chennai = 170 small divisions = 17 big divisions
    Hyderabad = 122 small divisions = 12 big divisions and 2 small divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 9:

The following table shows the life expectancy (average age to which people live) in various countries in a particular year. Represent this data by a bar graph.

Country	Japan	India	Britain	Ethiopia	Cambodia
Life expectancy (in years)	76	57	70	43	36

Answer 9:

We can draw the bar graph by following the given steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the names of the countries at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 10 years
1 small division = 1 year

Step 4.- Heights of the various bars:
   Japan = 76 small divisions = 7 big divisions and 6 small divisions
   India = 57 small divisions = 5 big divisions and 7 small divisions
   Britain = 70 small divisions = 7 big divisions
   Ethiopia = 43 small divisions = 4 big divisions and 3 small divisions
   Cambodia = 36 small divisions = 3 big divisions and 6 small divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

 

Question 10:

The following table shows the imports (in thousand crore rupees) made by India over the last five years. Draw a bar graph to represent this data.

Year	2001-02	2002-03	2003-04	2004-05	2005-06
Imports (in thousand crore rupees)	148	176	204	232	180

Answer 10:

We can draw the bar graph by following steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the years at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 20 thousand crore rupees
1 small division = 2 thousand crore rupees

Step 4.- Heights of the various bars:
    2001−02 = 74 small divisions = 7 big divisions and 4 small divisions
    2002−03 = 88 small divisions = 8 big divisions and 8 small divisions
    2003−04 = 102 small divisions = 10 big divisions and 2 small divisions
    2004−05 = 116 small divisions = 11 big divisions and 6 small divisions
    2005−06 = 90 small divisions = 9 big divisions

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 11:

The data given below shows the average rainfall in Udaipur from June to November of a certain year. Draw a bar graph to represent this information.

Month	June	July	Aug.	Sept.	Oct.	Nov
Average rainfall	25 cm	30 cm	40 cm	20 cm	10 cm	5 cm

Answer 11:

We can draw the bar graph by following the given steps:

Step 1- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2- Along OX, write the names of the months at the points taken at a uniform gap.

Step 3- Choose the scale:
1 big division = 5 cm
2 small divisions = 1 cm

Step 4- Heights of the various bars:
   June = 50 small divisions = 5 big divisions
   July = 60 small divisions = 6 big divisions
   August = 80 small divisions = 8 big divisions
   September = 40 small divisions = 4 big divisions
   October = 20 small divisions = 2 big divisions
   November = 10 small divisions = 1 big division

Step 5- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 12:

The following table shows the market position of different brands of soaps. Draw a bar graph to represent this data.

Brand	A	B	C	D	Other
Percentage of buyers	45	25	15	10	5

Answer 12:

We can draw the bar graph by following the given steps:

Step 1.- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2.- Along OX, write the names of the brands at the points that are taken at a uniform gap.

Step 3.- Choose the scale:
1 big division = 5% 
2 small divisions = 1%

Step 4.- Heights of the various bars:
   A = 90 small divisions = 9 big divisions
   B = 50 small divisions = 5 big divisions
   C = 30 small divisions = 3 big divisions
   D = 20 small divisions = 2 big divisions
   Others = 10 small divisions = 1 big division

Step 5.- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 13:

Gold prices on 4 consecutive Tuesdays were as under:

Week	First	Second	Third	Fourth
Rate per 10 gm (in Rs)	8500	8750	9050	9250

Draw a bar graph to show this imformation.

Answer 13:

We can draw the bar graph by following the given steps:

Step 1- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2- Along OX, write the names of the week at the points that are taken at a uniform gap.

Step 3- Choose the scale:
1 big division = Rs 500
1 small division = Rs 50

Step 4- Heights of the various bars:
    First week = 170 small divisions = 17 big divisions
    Second week = 175 small divisions = 17 big divisions and 5 small divisions
    Third week = 181 small divisions = 18 big divisions and 1 small division
    Fourth week = 185 small divisions = 18 big divisions and 5 small divisions

Step 5- Draw bars of equal width on the x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

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Question 14:

Various modes of transport used by 1850 students of a school are given below:

School bus	Private bus	Bicycle	Rickshaw	By foot
640	360	490	210	150

Draw a bar graph to represent the above data.

Answer 14:

We can draw the bar graph by following the given steps:

Step 1- On a graph paper, draw a horizontal line OX as x-axis and vertical line OY as y-axis.

Step 2- Along OX, write the names of the modes of transport at the points taken at a uniform gap.

Step 3- Choose the scale:
1 big division = 50 students
1 small division = 5 student

Step 4- Heights of the various bars:
    School bus = 128 small divisions = 12 big divisions and 8 small divisions
    Private bus = 72 small divisions = 7 big divisions and 2 small divisions
    Bicycle = 98 small divisions = 9 big divisions and 8 small divisions
    Rickshaw = 42 small divisions = 4 big divisions and 2 small divisions
    By foot = 30 small divisions = 3 big divisions

Step 5- Draw the bars of equal width on x-axis. The difference between the two bars should also be the same.

We get the following bar graph:

Question 15:

Look at the bar graph given below.



Read it care fully and answer the following questions.
(i) What information does the bar graph give?
(ii) In which subject is the student very good?
(iii) In which subject is the poor?
(iv) What is the average of his marks?

Answer 15:

(i) The bar graph shows the marks obtained by a student in an examination in various subjects.

(ii) The student is very good in mathematics.

(iii) The student is poor in Hindi.

(iv) Marks scored in English = 60
      Marks scored in Hindi = 35
      Marks scored in mathematics = 75
      Marks scored in social science = 50
      Marks scored in science = 60

∴ Average marks = $\frac{60+35+75+50+60}{5} = \frac{280}{5}=56$

Question 16:

In a survey or 85 families of a colony, the number of members in each family was recorded, and the data has been represented by the following bar graph.



Read the bar graph carefully and answer the questions given below:
(i) What information does the bar graph give?
(ii) How many families have 3 members?
(iii) How many people live alone?
(iv) Which type of family is the most common? How many members are there in each family of this kind?

Answer 16:

(i) The bar graph shows the number of members in each of the 85 families.

(ii) 40 families have three members each.

(iii) Number of people living alone = 85 − (5+40+25+15)
                                                        = 85 − 85
                                                        = 0

(iv) The most common family is that with three members.
       Each such family has three members .

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Question 17:

Given below is a bar graph showing the heights of five mountain peaks.



Read the bar graph carefully and answer the following questions:
(i) Which is the highest peak and what is its height?
(ii) What is the ratio of the heights of the highest peak and the next highest peak?
(iii) Arrange the heights of the given peaks in descending order.

Answer 17:

(i) Mount Everest is the highest peak and it's height is 8800 m.

(ii) Height of the highest peak, Mount Everest = 8800 m
      Height of the second highest peak, Kanchenjunga = 8200 m

                                                             Ratio = $\frac{8800}{8200} = \frac{44}{41} = 44 : 41$

(iii) Heights of the peaks are 6000 m, 8000 m, 7500 m, 8200 m and 8800 m.
      
Heights in descending order:

8200 m, 8000 m, 7500 m, 6000 m

Question 18:

In a public library, the librarian made the following observations in a particular week.
 

Days	Mon.	Tues.	Wed.	Thurs.	Fri.	Sat.
Newspaper readers	350	400	500	450	550	450
Magazine readers	200	450	300	250	100	50

(i) Draw a double bar graph choosing an appropriate scale.
(ii) On which day, the number of readers in the library was maximum?
(iii) What is the mean number of magazine readers per day?

Answer 18:

(i)

(ii) On Tuesday the number os readers in the library were maximum = 400 + 450 =850
(iii) Mean nnumber of magazine readers = $\frac{200+450+300+250+100+50}{6}=\frac{1350}{6}=225$

Question 19:

On a particular day in a school, the attendance in each of the classes from VI to X has been recorded as under.
 

Class	VI	VII	VIII	IX	X
Total no. of students	95	90	82	75	68
Number of students present on that day	92	85	78	69	62

Draw a double bar graph, choosing an appropriate scale.
Using the bar graph, answer the questions given below.
(i) Which class has the maximum number of students?
(ii) Find the ratio of number of students present to the total number of students in Class VII.
(iii) What per cent of Class IX students were absent?

Answer 19:

(i) Maximaum number of students are in Class VI
(ii) Ratio = $\frac{85}{90}=\frac{17}{18}$
(iii) Percentage of class IX absent =$\frac{6}{75}\times 100=8$%

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Question 20:

Consider the data, showing the average daily hours of sunshine in two cities Aberdeen and Margate for six months of an year.
 

Month	January	February	March	April	May	June
Number of hours of sunshine in Aberdeen	2	$3\frac{1}{4}$	4	$4\frac{1}{2}$	$7\frac{3}{4}$	8
Number of hours of sunshine in Margate	$1\frac{1}{2}$	3	$3\frac{1}{2}$	6	$5\frac{1}{2}$	$6\frac{1}{2}$

Draw a double bar graph, to depict the above information.
(i) In which month does Aberdeen have maximum sunlight?
(ii) In which month does Margate have minimum sunlight?

Answer 20:

(i) Maximum sunlight in Aberdeen is during June (8 hours)
(ii) Minimum sunlight in Margate is during January (1.5 hours)

Question 21:

The table given below shows the population of four towns over two years.
 

Towns	A	B	C	D
2016	640000	830000	460000	290000
2017	750000	920000	630000	320000

(i) Draw a double bar graph using approprtate scale to depict the information given above.
(ii) In which town was the population growth maximum?
(iii) In which town was the population growth least?

Answer 21:

(i) 


(ii) Maximum population growth was in Town A
(iii) Least population growth in Town D

Question 22:

Study the double bar graph given below and answer the questions that follow.

Figure

(i) What has been compared in the given double bar graph?

(ii) What is the ratio of minimum temperatures in the year 2015 to the year 2016 in the month of November?

(iii) Name the months in which the minimum temperature in 2015 was greater than that in 2016?

(iv) Find the average minimum temperature for the year 2016 for the given four months.

(v) In which month is the variation in two temperatures maximum?

Answer 22:

(i) Minimum temperature for the monts of Nov, Dec, Jan and Feb of 2015 and 2016 have been compared.
(ii) Ratio of minimum temperature in 2015 to minimum temperature in 2016 during the month of Nov = $\frac{18}{14}=\frac{9}{7}$ 
$\Rightarrow \mathrm{Ratio}=9:7$
(iii) In November and February the minimum temperature in 2015 was greater than that of 2016.
(iv) Average minimum temperature for the year 2016 = $\frac{14+13+8+9}{4}=\frac{44}{4}=11$º C
(v) November variation = 18 − 14 = 4
December variation = 13 − 11 = 2
January variation = 8 − 5 = 3
February variation = 11 − 9 = 2 
During November the variation in two temperatures is maximum.