RBSE Solutions Class 6 Maths Chapter 15 Data Handling Exercise 15.1

 

Question 1. Identify the primary and secondary data from the following:
(i) Numbers of students present from each class during morning prayer on a particular day.
(ii) Numbers of students from each caste gathered from the student's attendance
(iii) Number of vehicles passing through a road between 9 a.m. to 11 a.m. on a particular day.
(iv) Listing the distances of Jaipur from major towns of Rajasthan after looking at map.
Answer:
(i) Primary data
(ii) Secondary data
(iii) Primary data
(iv) Secondary data
Collecting data directly from its source makes it primary data, while using already existing data is secondary data. For instance, counting students present in a class is a direct observation.
In simple words: Primary data is what you collect yourself, like counting cars. Secondary data is information someone else has already gathered, like looking up distances on a map.

🎯 Exam Tip: Remember, primary data is collected by the user directly for a specific purpose, while secondary data is gathered from existing sources. This distinction is crucial in data handling.

 

Question 2. The following is data about the ages of 30 students of class VI. Prepare a table using tally marks and answer the following questions:
11, 12, 11, 13, 14, 11, 12, 13, 15, 13, 13, 16, 14, 13, 14, 13, 12, 14, 13, 12, 14, 14, 13, 12, 13, 14
(i) How many students have completed 13 years of age?
(ii) Maximum number of students are of which age?
(iii) How many students have not yet completed 14 years of age?
Answer:

(i) Students who have completed 13 years of age means students who are 13 years old or older. So, these are students aged 13, 14, 15, and 16 years. Number of students = 11 + 8 + 1 + 1 = 21 students.
(ii) From the tally table, the maximum number of students (11 students) are 13 years old.
(iii) Students who have not yet completed 14 years of age means students who are younger than 14. So, these are students aged 11, 12, and 13 years. Number of students = 3 + 6 + 11 = 20 students.
In simple words: We counted how many students are each age. Then we used these counts to answer questions about students in different age groups.

🎯 Exam Tip: Always make sure your tally marks are clear and easy to count in groups of five. Double-check your totals to ensure they match the initial number of data points.

 

Question 3. 25 students participated in an Essay competition on the topic "Clean India-Healthy India". Following is the data about their marks obtained out of maximum marks 10.
6, 7, 7, 5, 8, 9, 8, 6, 7, 5, 8, 6, 6, 5, 4, 7, 6, 8, 8, 9, 7, 5, 9, 8, 10
Prepare a table using tally marks and answer the following questions:
(i) Number of students who obtained less than or equal to 6 marks.
(ii) Number of students who obtained more than 6 marks.
(iii) Number of students who obtained 8 marks.
Answer:

(i) The number of students who obtained less than or equal to 6 marks includes students who scored 4, 5, or 6. Total students = 1 (for 4 marks) + 4 (for 5 marks) + 5 (for 6 marks) = 10 students.
(ii) The number of students who obtained more than 6 marks includes students who scored 7, 8, 9, or 10. Total students = 5 (for 7 marks) + 6 (for 8 marks) + 3 (for 9 marks) + 1 (for 10 marks) = 15 students.
(iii) From the table, 6 students obtained 8 marks.
In simple words: First, we counted how many students got each score and showed it with tally marks. Then, we used these counts to find out how many students got scores in specific ranges.

🎯 Exam Tip: When dealing with "less than or equal to" or "more than" conditions, carefully include or exclude the boundary value as per the question. Summing correctly from your tally table is key.

 

Question 4. Observe the pictograph and answer the following questions:
(i) Which family has maximum members?
(ii) Which family has minimum members?
(iii) What is the difference between number of family members of families D and C?
(iv) How many total number of members in all five families?
Answer:

(i) Family D has the maximum number of members, with 6 members.
(ii) Family C has the minimum number of members, with 2 members.
(iii) The difference between the number of family members of Family D and Family C is \( 6 - 2 = 4 \).
(iv) The total number of members in all five families is calculated by adding the members of each family: \( 5 + 4 + 2 + 6 + 4 = 21 \) members. This pictograph helps us visually compare family sizes quickly.
In simple words: We counted the happy faces for each family. This showed us which family had the most or least people, the difference between them, and the total number of people in all families together.

🎯 Exam Tip: Always pay attention to the key (what each symbol represents) in a pictograph before counting. Carefully count the symbols to avoid errors.

 

Question 5. The pictograph below shows how many envelops were sold by a post office during a week. Use the pictograph to answer the following questions:
(i) How many envelops were sold on Wednesday?
(ii) On which day, maximum number of envelops were sold?
Answer:

(i) On Wednesday, 5 symbols are shown, and each symbol represents 5 envelops. So, the number of envelops sold on Wednesday is \( 5 \times 5 = 25 \) envelops.
(ii) Monday had 7 symbols, which is the highest number of symbols. This means the maximum number of envelops were sold on Monday ( \( 7 \times 5 = 35 \) envelops).
(iii) If one envelop costs Rs 5, then the cost of envelops sold on Monday would be \( 7 \times 5 \times 5 = 175 \). This calculation considers the number of symbols, the value of each symbol in envelops, and the cost per envelop.
(iv) The total number of symbols sold during the week is \( 7 + 4 + 5 + 6 + 3 + 2 = 27 \). Since each symbol is 5 envelops, the total envelops sold are \( 27 \times 5 = 135 \) envelops. The total cost for these envelops would be \( 135 \times 5 = 675 \) Rs.
In simple words: We counted the envelope pictures and multiplied by 5 to find the total envelops sold each day. We found the day with the most sales and also calculated the total sales and cost for the whole week.

🎯 Exam Tip: When a pictograph symbol has a value greater than one, always remember to multiply the number of symbols by that value to get the actual quantity. Carefully read all parts of the question, even if they are implied within the "Solution" section.

 

Question 6. The following pictograph shows the number of students who like to play different sports in a class of 30 students:
(i) How many students play kho – kho?
(ii) Which sport is played by maximum number of students?
(iii) How many students play none of the sports?
Answer:

(i) From the pictograph, there are 8 symbols next to Kho-Kho. So, 8 students play Kho-Kho.
(ii) Cricket has the most symbols (11 students), indicating it is played by the maximum number of students.
(iii) To find students who play none of the sports, we subtract the total number of students playing sports from the total class strength. The total number of students who play sports is \( 6 (\text{Football}) + 8 (\text{Kho-Kho}) + 5 (\text{Volley ball}) + 11 (\text{Cricket}) = 30 \) students. Since the total class strength is also 30, the number of students who play none of the sports is \( 30 - 30 = 0 \). This shows that every student in the class plays at least one of these sports.
In simple words: We counted the student symbols for each sport to see how many play each game. We found which game was most popular and if any students didn't play any of the listed sports.

🎯 Exam Tip: Always double-check that the sum of all categories in a pictograph matches the given total population to verify your counts and identify if any data points are missing or extra.