NCERT Solutions for Class 7 maths chapter 3

Data Handlings

NCERT Solutions for Class 7 maths chapter 3 Exercise 3.3

Question 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?

Answer

The bar graph represents the pets owned by the students.

(a) The most popular pet is Cat

(b) 8 students

Question 2

Read the bar graph (Fig 3.4) which shows the number of books sold by a bookstore during five consecutive years and answer the following questions:

(i) About how many books were sold in 1989? 1990? 1992?

(ii) In which year were about 475 books sold? About 225 books sold?

iii) In which years were fewer than 250 books sold?

(iv) Can you explain how you would estimate the number of books sold in 1989?

Answer

(i)175 books were sold in the year 1989.

475 books were sold in the year 1990.

225 books were sold in the year 1992.

(ii)475 books were sold in the year 1990.

225 books were sold in the year 1992.

(iii) 1989 and 1992

(iv)By reading we calculate 180 books sold in the year 1989

Question 3

Number of children in six different classes are given below. Represent the data on a bar graph

(a) How would you choose a scale?

(b) Answer the following questions:

(i) Which class has the maximum number of children? And the minimum?

(ii) Find the ratio of students of class sixth to the students of class eight.

Answer

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(a)By data represented in bar graph
Scale 1 unit = 10 children

(b) (i)Fifth class has the maximum number of children . Senenth class has the minimum number of children

(ii) Ratio
=

= 6: 5

Question 4

The performance of a student in 1st Term and 2nd Term is given. Draw a double bar graph choosing appropriate scale and answer the following:

(i) In which subject, has the child improved his performance the most?

(ii) In which subject is the improvement the least?

(iii) Has the performance gone down in any subject?

Answer

(i) The child has improved his performance in Maths.

(ii) The child improvement was the least in S. Science.

(iii) Yes the performance In Hindi has gone down.

Question 5

Consider this data collected from a survey of a colony.

(i) Draw a double bar graph choosing an appropriate scale.

What do you infer from the bar graph?

(ii) Which sport is most popular?

(iii) Which is more preferred, watching or participating in sports?

Answer

(i) The fig above bar graph. Which represents the people who are watching or participating in different sports.

(ii) Cricket is the most popular sport.

(iii)Watching sports has more prefered

Question 6

Take the data giving the minimum and the maximum temperature of various cities given in the beginning of this Chapter (Table 3.1). Plot a double bar graph using the data and answer the following:

(i) Which city has the largest difference in the minimum and maximum temperature on the given date?

(ii) Which is the hottest city and which is the coldest city?

(iii) Name two cities where maximum temperature of one was less than the minimum temperature of the other.

(iv) Name the city which has the least difference between its minimum and the maximum temperature.

Answer

(i) Jammu has the largest difference temperature
Maximum =41^oC and minimum 26^oC So difference is 15^oC.

(ii)Jammu is the hottest city and Bangalore is the coldest city.

(iii) Bangalore and Jaipur, Bangalore and Ahmedabad. The maximum temperature of Bangalore, was 28^oC, while minimum temperature of both Ahmadabad and Jaipur was 29^oC.

(iv) Mumbai has the least difference between its minimum and the maximum temperature.
Maximum temperature =32^oC and minimum temperature =27 ^oC
So difference = 5^oC