WBBSE Solutions For Class 8 Maths Chapter 2 Pie Chart 

Pie Chart

This is the pictograph of how many clay dolls are made by Shahnaj’s father Niamat chacha (uncle) for the first 4 days of this week.

Let’s find answers to the questions from the pictograph.

1. Let’s write which day of the week Niamat chacha made the most number of clay dolls.
Solution: Wednesday

2. Let’s write how many clay dolls Niamat chacha made on Tuesday.
Solution: 90

3. Let’s write which day of the week he made the least number of clay dolls.
Solution: Thursday

4. Let’s write how many clay dolls he made on Monday.
Solution: 80

Read and Learn More WBBSE Solutions For Class 8 Maths

To explain the data collected by me, my friend Amia made a bar diagram.

Number of clay dolls →

Let’s find the answers from the bardiagram of Amia.

1. Let’s write how many clay dolls Niamat chacha made on Monday.
Solution: 80

2. Let’s write when he made clay dolls least.
Solution: Thursday

3. Let’s write how many more clay dolls he made on Monday. than on Thursday.
Solution: 20

Let’s see in the bar diagram how many clay dolls Pritambabu and Amina Bibi made in first four days in the week.

Let’s see double columned bar diagram and find the answers to the questions below 

1. Let’s write between Pritambabu and Amina Bibi who made clay dolls most on Monday and how many clay dolls they made most.
Solution: On Monday Pritambabu made more clay dolls. Number of
more clay dolls made on Monday = (130 – 110) = 20

2. Let’s write on which days of the week Amina Bibi more clay dolls from Pritambabu and how many more clay dolls did she make.
Solution: On Wednesday and Thursday Amina Bibi made more clay dolls than Pritambabu. Number of more clay dolls on Wednesday = (125-85) = 40

Number of more clay dolls on Thursday = (95 – 90) = 5

Pie Chart Exercise 2

In this year we have arranged to explain the making of various types of science models in the science exhibition of our school. Every day students of many schools and the guardians are coming to see in huge number. Let’s list those who have come in the exhibition today from 10 am to 12 noon on Sunday.

Let, Women – W

Men – M

Boy- B

Girl – G

[B, G, B, M, G, G, M, B, W, B, W, G, W, G, G, M, M, W, B, B, B, W, W, G, G, W, B, M, M, B, G, G,.B, W, M, M, W, M, M, G, G, W, M]

Let’s make a frequency table by the raw data using tally marks and make a bar diagram.

Solution: Frequency table

Bar diagram:

Ayan made a list of the hobbies of 30 students in our class:

Meher made a bar diagram of the data above.

The data is expressed through the circular regional picture beside. We see the sectors of reading and drawing are the largest and same in size.

Again, the sector of reading story book and playing are the smallest and similar in size.

So one sector indicates one part of the data and the area of one sector along with the quantity of a part of the data is proportional.

During recess the part of the total students singing = \(\frac{7 \text { people }}{30 \text { people }}=\frac{7}{30}\)

During recess the part of total studens drawing picture = \(\frac{7}{30}\)

But during recess the part of the total students reading story books = \(\frac{5}{30}=\frac{1}{6}\)

But during recess the part of the total students playing drama = \(\frac{1}{6}\)

And during recess the part of the students dancing = \(\frac{1}{5}\)

So, one sector of singing and drawing pictures fill up the \(\frac{14}{30}\) part of the total circular region.

During recess, the sector of dancing fills up the \(\frac{1}{5}\) part of the total circular region.

What is the writing system of data through this circular picture called?

It is called pie chart or circular regional chart.

Let’s try to make the sectors proportional to different parts of the data.

Let’s see the chart below and understand the data.

The pie chart of running conveyance on road today from 11 am to 12 noon.

We see – 1 Most running Bus

2. Least running Cycle.

3. Let’s write 2 cars running equally in numbers.

Answer: Lorry and Taxi

4. Let’s write how many parts the sector of a running taxi is of the circular region?
Solution:

\(\frac{14}{100}=\frac{7}{50}\)

It has been raining heavily since this morning. So most of the students can not come to school. Tathagatha makes a pie chart of the numbers of students who are present and absent in his class.

We see most of the students of Tathagata’s class are j Present] [ Present / Absent ]

What part of the circular region is denoted by the sector absent?
Solution:

\(\frac{40}{100}=\frac{2}{5}\)

Let’s make a pie chart of the data given in the list. Let us convert the percentage into fraction.

Now when I divide a circular region into some sectors, whose central angles are 144°, 72°, 18°, 90°, 36°.

∠AOB = 90°, ∠BOC = 18°, ∠COD = 72°

∠DOE = 144°, ∠AOE = 36°

Question 1. Last year in the month of April, 23 days were denoted to academics in Rohit’s school. Rohit has wtitten the number of students present in those 23 days in his school.

 

Now I make the frequency chart with tally mark and make bar diagram with the help of this, chart.

Solution: Frequency chart

Bar diagram:

Question 2. Now I also make a bar diagram showing how many students out of a total of 40 students help in their household work (in house) during holidays. Let’s see the bar diagram and try to find out the answers of various questions.
Solution:

1. Let’s write how many students of our class do domestic work every holiday from the bar diagram and for how long.
Solution :

1. 6 students do household work for 5 hours.
2. 14 students do the work for 4 hours.
3. 12 students do the work for 3 hours.
4. 8 students do the work for 2 hours.

2. Let’s write how many students help in their domestic work for maximum time.
Solution: 14 students

3. Let’s write how many students help in their domestic work for two hours on every holiday.
Solution: 8 students

Question 3. Let’s see the pie chart below and find the answers to the following questions.

1. Let’s write how many parts of the total circular region is the sector of the auidence of Folk song.
Solution:

\(20 \%=\frac{20}{100}=\frac{1}{5}\) part

2. Let’s write from the pie chart which type of songs has the most number of listeners.
Solution: Audience of modern songs is the most in number.

3. Let’s write which type of songs has the least number of listeners.
Solution: Audience of classical music is the least.

2. The pie-chart of what kind of programmes the audience likes :

1. Let’s write how many part of the total circular region is the sector of the audience who watch news in the pie chart.
Solution:

\(\frac{20^{\circ}}{100^{\circ}}=\frac{1}{5}\) part

2. Let’s write what kind of programme gets the most audience.
Solution: Entertainment based

3. Let’s write what kind of programme gets the least audience.
Solution: Information based

4. Let’s write how many parts of the total audience watch the programmes of sports.
90°
Solution: \(\frac{90^{\circ}}{360^{\circ}}=\frac{1}{4}\) part

Question 4. I write the percentage of marks which Shuvam has secured in the final examination of class V below
Solution:

Let’s make a pie chart of this information and write the central angle of each sector

Hindi = \(\frac{15}{100}=15 \%=\frac{15}{100} \times 360^{\circ}\) = 54°

English = \(\frac{20}{100}=20 \%=\frac{20}{100} \times 360^{\circ}\) = 72°

Maths = \(\frac{30}{100}=30 \%=\frac{30}{100} \times 360^{\circ}\) = 108°

Environment = \(\frac{15}{100}=15 \%=\frac{15}{100} \times 360^{\circ}\) = 54°

Physical Education = \(\frac{20}{100}=20 \%=\frac{20}{100} \times 360^{\circ}\) = 72°

∠AOB = 54°, ∠BOC = 72°, ∠COD = 108°, ∠DOE = 54°, ∠AOE = 72°

Question 5. There is a shop of Madhubabu in our locality. I made a list of various types of things which were being sold in his shop for a particular day.
Solution:

Now I try to make a pie-chart based on the above information.

Hints: First convert into fractions.

Total number of things sold that day = Rs. (320 +100+160+140)= Rs. 720

∴ Common bread sold = \(\frac{320}{720}\) = \(\frac{4}{9}\)

In the circular region of my pie chart, the central angle of the sector selling Common bread = 360° x \(\frac{4}{9}\) = 4 x 40° = 160°.

In the same way, the central angle of selling Slice bread is = 50°

The central angle of the sector of selling Cake is = 80°

The central angle of the sector of selling Biscuits is = 70°

Let’s draw a pie chart myself.

Question 6. I have made a list of things of what the students of class VIII of both the sections like to do during their leisure. (One ‘ student can like only one subject).
Solution:

Let’s work out from this data what parts of the total students like which subjects.

Let’s find the central angle of each sector and make pie chart accordingly.

Answer: Total number of the students = 20 + 25 + 27 + 28 + 20 = 120

Song = \(\frac{20}{120}=\frac{1}{6}=\frac{1}{6} \times 360^{\circ}\) = 60

Poem = \(\frac{25}{120}=\frac{5}{24}=\frac{5}{24} \times 360^{\circ}\) = 75

Dancing = \(\frac{27}{120}=\frac{9}{40}=\frac{9}{40} \times 360^{\circ}\) = 81

Drama = \(\frac{28}{120}=\frac{7}{30}=\frac{7}{30} \times 360^{\circ}\) = 84

Drawing = \(\frac{20}{120}=\frac{1}{6}=\frac{1}{6} \times 360^{\circ}\) = 60

Question 7. I have made a model. I made a chart of expenditure of buying materials.
Solution:

Let’s make a pie chart with this information and write the central angle of the sectors.

Total expenditure = (9 + 12 + 25 + 6 + 8) = 60

Art paper = \(\frac{9}{60} \times 360^{\circ}\) = 54°

Sketch pen = \(\frac{12}{60} \times 360^{\circ}\) = 72°

Scissor = \(\frac{25}{60} \times 360^{\circ}\) = 150°

Colour ribbon =  \(\frac{6}{60} \times 360^{\circ}\) = 36°

Pitch board = \(\frac{8}{60} \times 360^{\circ}\) = 48°

Question 8. I made a list of the painters based on the likings of 450 spectators coming to an art exhibition one day.
Solution:

Let’s make a pie chart with this information and write the central angle of the sectors.

Jaminy Roy = \(\frac{150}{450} \times 360^{\circ}\) = 120°

Nandalal Basu = \(\frac{120}{450} \times 360^{\circ}\) = 96°

Chintamoni Kar = \(\frac{80}{450} \times 360^{\circ}\) = 64°

Ganesh Pain = \(\frac{100}{450} \times 360^{\circ}\) = 80°

Nandalal Bose Pie Chart:

Question 9. A chart was made by asking the name of the favourite >eason to a group of 180 boys.
Solution:

Let’s find the answers to the questions from the pie chart below.

1. Let’s write which season is liked by most of the students and how none liked it.
Solution: Most students like winter.

No of students = 72

2. Let’s write which sensor is liked by the least number of students..
Solution: The least number of students like Rainy season.

3. Let’s write how many students like summer.
Solution: 36 students like summer.

4. Let’s write which season is described by the smallest sector.
Solution: The smallest sector denotes rainy season.

5. Let’s see the pie chart and make two more new questions. Try to find answers to them.

1. How many people like rainy season ?
Solution: 18 persons like rainy season.

2. How many people like spring ?
Solution: 54 people like spring.