Ncert Solutions For Class 8 Maths Ex 5.2

1. A survey was made to find the type of music a group of people liked in a town. The pie chart given below shows the information regarding that survey. From the pie chart, give the answer for the following questions.

(a) If 60 people liked semi classical music then how many people were surveyed?

(b) Which music is liked by the minimum number of people?

(c) If a company make 2000 CD’s then how many of each type would they make?

Answer:

(a) People who like semi – classical music = 30%

This 30% represents 60 people.

100% represents = $\frac{60 \times 100}{30}$ = 200 people

Hence, 200 people were surveyed.

 

(b) From the pie chart we can see that light music is represented by the minimum part of the pie chart. Therefore, light music is least liked by people.

 

(c) Number of Classical music CDs = 20% of 2000

= $\frac{20 \times 2000}{100}$

= 400 CDs

 

Number of Semi – Classical music CDs = 30% of 2000

= $\frac{30 \times 2000}{100}$

= 600 CDs

 

Number of Light music CDs = 10% of 2000

= $\frac{10 \times 2000}{100}$

= 200 CDs

 

Number of Folk music CDs = 40% of 2000

= $\frac{40 \times 2000}{100}$

= 800 CDs

 

2. In a survey 720 people were asked about their favorite season from summer, winter and monsoon. Answer the following questions according to the given information.

(a) Which season got the minimum votes?

(b) What will be the central angle of each season?

(c) Draw pie chart for the given information.

Festival	Votes
Summer	160
Winter	340
Monsoon	220

 

Answer:

(a) Winter season got the maximum number of votes.

 

(b) Total number of votes = 160 + 340 220 = 720

Central angle for summer = $\frac{160 \times 360^{\circ}}{720}$

= $\frac{160}{2}$

= $80^{\circ}$

 

Central angle for winter    = $\frac{340 \times 360^{\circ}}{720}$

= $\frac{340}{2}$

= $170^{\circ}$

 

Central angle for monsoon = $\frac{220 \times 360^{\circ}}{720}$

= $\frac{220}{2}$

= $110^{\circ}$

(c) Pie chart for the above information

 

3. According to the information given below, draw the pie chart representing it. The table below shows the colors liked by a group of people.

Colors	Number of People
Blue	36
Red	18
Green	12
Yellow	6
Total	72

 

Answer:

Total number of votes = 72

Central angle for Blue = $\frac{36 \times 360^{\circ}}{72}$

= $\frac{360}{2}$

= $180^{\circ}$

 

Central angle for Red    = $\frac{18 \times 360^{\circ}}{72}$

= $\frac{360}{4}$

= $90^{\circ}$

 

Central angle for Green = $\frac{12 \times 360^{\circ}}{72}$

= $\frac{360}{6}$

= $60^{\circ}$

 

Central angle for Yellow = $\frac{6 \times 360^{\circ}}{72}$

= $\frac{360}{12}$

= $30^{\circ}$

 

Pie chart as above information

 

4. The pie chart given below gives the information about the marks scored by a student in 5 subjects which are English, Math, Science, Hindi and Social Science. The total marks obtained by the student were 480.

(a) The student scored 108 marks in which subject?

(b) What is the difference between the marks of Math and Hindi? Which subject has more marks?

(c) Check whether the summation of Math and Hindi is more than that of Science and Social Science.

Answer:

(a) 480 marks is $360^{\circ}$. Therefore, 108 marks give the following central angle.

= $\frac{108 \times 360}{480}$

= $81^{\circ}$

Therefore, the subject is Science.

 

(b) Marks obtained in Math = 90% of 480

= $\frac{90 \times 480}{360}$

= 120 marks

 

Marks obtained in Hindi =57% of 480

= $\frac{57 \times 480}{360}$

= 76 marks

 

The difference between Math and Hindi marks is 120 – 76 = 44 marks.

In Math, student scored 44 marks more compared to Hindi.

 

(c) Marks obtained in Social Science = 69% of 480

= $\frac{69 \times 480}{360}$

= 92 marks

 

Marks obtained in Science = 81% of 480

= $\frac{81 \times 480}{360}$

= 108 marks

 

Summation of Math and Hindi = 120 + 76 = 196 marks

Summation of Science and Social Science = 92 + 108 = 200 marks

Summation of Science and Social Science is more than that of Math and Hindi.

 

5. The number of students in a school who are speaking various languages is as given below. Draw the pie chart according to the given information.

Language	English	Hindi	Tamil	Telugu	Marathi	Total
Number of Students	20	6	5	3	2	36

 

Answer:

The central angle of each language is calculated as given below.

 

Central angle of English language = $\frac{20 \times 360}{36}$

= $200^{\circ}$

Central angle of Hindi language    = $\frac{6 \times 360}{36}$

= $60^{\circ}$

Central angle of Tamil language = $\frac{5 \times 360}{36}$

= $50^{\circ}$

Central angle of Telugu language = $\frac{3 \times 360}{36}$

= $30^{\circ}$

Central angle of Marathi language = $\frac{2 \times 360}{36}$

= $20^{\circ}$

 

Pie chart of the data: