Rd Sharma 2018 Solutions for Class 6 Math Chapter 1 Knowing Our Numbers are provided here with simple step-by-step explanations. These solutions for Knowing Our Numbers are extremely popular among Class 6 students for Math Knowing Our Numbers Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Rd Sharma 2018 Book of Class 6 Math Chapter 1 are provided here for you for free. You will also love the ad-free experience on Meritnationâ€™s Rd Sharma 2018 Solutions. All Rd Sharma 2018 Solutions for class Class 6 Math are prepared by experts and are 100% accurate.

#### Page No 21.4:

#### Question 1:

Define the following terms:

(i) Observations

(ii) data

(iii) Frequency of an observation

(iv) Frequency distribution

#### Answer:

(i) Observation is the active acquisition of information from a primary source.

(ii) A collection of facts such as values and measurements are called data.

(iii) Number of times an observation has occurred in a given data.

(iv) A frequency distribution is an arrangement of instances in which a variable takes each of its possible values. A frequency distribution depicts a summarised grouping of data divided into mutually exclusive classes and the number of occurrences in those classes.

#### Page No 21.4:

#### Question 2:

The final marks in mathematics of 30 students are as follows:

53, 61, 48, 60, 78, 68, 55, 100, 67, 90

75, 88, 77, 37, 84, 58, 60, 48, 62, 56

44, 58, 52, 64, 98, 59, 70, 39, 50, 60

(i) Arrange these marks in the ascending order. 30 to 39 one group, 40 to 49 second group, etc.

(ii) What is the highest score?

(iii) What is the lowest score?

(iv) What is the range?

(v) If 40 is the pass mark how many have failed?

(vi) How many have scored 75 or more?

(vii) Which observations between 50 and 60 have not actually appeared?

(viii) How many have scored less than 50?

#### Answer:

(i)Frequency distribution of the given marks in mathematics of 30 students:

30 − 39 | 37, 39 |

40 − 49 | 44, 48, 48 |

50 − 59 | 50, 52, 53, 55, 56, 58, 58, 59 |

60 − 69 | 60, 60, 60, 61, 62, 64, 67, 68 |

70 − 79 | 70, 75, 77, 78 |

80 − 89 | 84, 88 |

90 − 99 | 90, 98 |

100 - 109 | 100 |

(ii) From the given data we can see that the highest score is 100.

(iii) The above data shows 37 as the lowest score.

(iv) Range = Highest score − Lowest score = 100 − 37 = 63

(v) If 40 is the pass marks, students who have scored less than 40 have failed. So, the students who have scored 37 and 39 have failed.

∴ Number of students that have failed in the exam = 2

(vi) Students who have scored 75, 77, 78, 84, 88, 90, 98 and 100 are the ones to score more than 75.

∴ Number of students who scored 75 or more = 8

(vii) The observations 51, 54 and 57 have not appeared in the data range of 50-60.

(viii) Students who have scored 37, 39, 44, 48 and 48 are the ones to score less than 50.

∴ Number of students who got less than 50 = 5

#### Page No 21.5:

#### Question 3:

The weights of new born babies (in kg) in a hospital on a particular day are as follow:

2.3, 2.2, 2.1, 2.7, 2.6, 3.0, 2.5, 2.9, 2.8, 3.1, 2.5, 2.8, 2.7, 2.9, 2.4

(i) Rearrange the weights in descending order.

(ii) Determine the highest weight.

(iii) Determine the lowest weight.

(iv) Determine the range.

(v) How many babies were born on that day?

(vi) How many babies weigh below 2.5 kg?

(vii) How many babies weigh more than 2.8?

(viii) How many babies weigh 2.8 kg?

#### Answer:

(i) Arranging the weights of the newborn babies in the descending order, we get: 3.1, 3.0, 2.9, 2.9, 2.8, 2.8, 2.7, 2.7, 2.6, 2.5, 2.5, 2.4, 2.3, 2.2, 2.1.

(ii) In a descending order, the first number is always the highest.

∴ Highest weight = 3.1kg.

(iii) In a descending order, the last number is always the lowest.

∴ Lowest weight = 2.1kg.

(iv) Range = Highest weight − Lowest weight

(v) We can count the number of babies born on that particular day by counting the number of observations.

∴ Number of babies born on that day = 15

(vi) Babies which weigh 2.1, 2.2, 2.3 and 2.4kg are the ones to weigh less than 2.5kg.

∴ Number of babies below 2.5kg = 4

(vii) Babies which weigh 2.9, 2.9, 3.0 and 3.1kg are the ones to weigh more than 2.8kg.â€‹

∴ Number of babies above 2.8kg = 4

(viii) Number of babies weighing 2.8kg = 2

#### Page No 21.5:

#### Question 4:

Following data gives the number of children in 40 families:

1, 2, 6, 5, 1, 5, 1, 3, 2, 6, 2, 3, 4, 2, 0, 0, 4, 4, 3, 2

2, 0, 0, 1, 2, 2, 4, 3, 2, 1, 0, 5, 1, 2, 4, 3, 4, 1, 6, 2

Represent it in the form of a frequency distribution.

#### Answer:

Frequency distribution of the given data:

#### Page No 21.5:

#### Question 5:

Prepare a frequency table of the following scores obtained by 50 students in a test:

42 | 51 | 21 | 42 | 37 | 37 | 42 | 49 | 38 | 52 |

7 | 33 | 17 | 44 | 39 | 7 | 14 | 27 | 39 | 42 |

42 | 62 | 37 | 39 | 67 | 51 | 53 | 53 | 59 | 41 |

29 | 38 | 27 | 31 | 54 | 19 | 53 | 51 | 22 | 61 |

42 | 39 | 59 | 47 | 33 | 34 | 16 | 37 | 57 | 43 |

#### Answer:

Frequency distribution table of the given scores:

#### Page No 21.5:

#### Question 6:

A die was thrown 25 times and following scores were obtained:

1 | 5 | 2 | 4 | 3 |

6 | 1 | 4 | 2 | 5 |

1 | 6 | 2 | 6 | 3 |

5 | 4 | 1 | 3 | 2 |

3 | 6 | 1 | 5 | 2 |

Prepare a frequency table of the scores.

#### Answer:

Frequency distribution table of the given data:

#### Page No 21.5:

#### Question 7:

In a study of number of accidents per day, the observations for 30 days were obtained as follows:

6 | 3 | 5 | 6 | 4 | 3 | 2 | 5 | 4 | 2 |

4 | 2 | 1 | 2 | 2 | 0 | 5 | 4 | 6 | 1 |

6 | 0 | 5 | 3 | 6 | 1 | 5 | 5 | 2 | 6 |

Prepare a frequency distribution table.

#### Answer:

Frequency distribution table of the given number of accidents per day is given below:

#### Page No 21.6:

#### Question 8:

Prepare a frequency table of the following ages (in years) of 30 students of class VIII in your school:

13, 14, 13, 12, 14, 13, 14, 15, 13, 14, 13, 14, 16, 12, 14

13, 14, 15, 16, 13, 14, 13, 12, 17, 13, 12, 13, 13, 13, 14.

#### Answer:

Frequency distribution table of the given ages (in years) of 30 students:

#### Page No 21.6:

#### Question 9:

Following figures relate the weekly wages (in Rs.) of 15 workers in a factory:

300, 250, 200, 250, 200, 150, 350, 200, 250, 200, 150, 300, 150, 200, 250

Prepare a frequency table,

(i) What is the range in wages (in Rs)?

(ii) How many Workers are getting Rs 350?

(iii) How many workers are getting the minimum wages?

#### Answer:

Frequency distribution of the given weekly wages of 15 workers:

(i) Minimum wage = Rs. 150

Maximum wage = Rs. 350

∴ Range = Maximum wage − Minimum wage

= Rs. 200

(iii) Here, minimum wage Rs. 150

Number of workers getting Rs. 150 = 3 workers

∴ Number of workers getting minimum wages = 3 workers

#### Page No 21.6:

#### Question 10:

Construct a frequency distribution table for the following marks obtained by 25 students in a history test in class VI of a school:

9, 17, 12, 20, 9, 18, 25, 17, 19, 9, 12, 9, 12, 18, 17, 19, 20, 25, 9, 12, 17, 19, 19, 20, 9

(i) What is the range of marks?

(ii) What is the highest mark?

(iii) Which mark is occurring more frequently?

#### Answer:

Frequency distribution of the given marks:

(i) Highest marks = 25

Lowest marks = 9

∴ Range = Highest marks − Lowest marks

(ii) Highest marks = 25

(iii) From the frequency table we can say that 6 students scored 9 marks in the History test.

∴ The number 9 occurs more frequently.

#### Page No 21.6:

#### Question 11:

In a mathematics test following marks were obtained by 40 students of class VI. Arrange these marks in a table using, tally marks.

8 | 1 | 3 | 7 | 6 | 5 | 5 | 4 | 4 | 2 |

4 | 9 | 5 | 3 | 7 | 1 | 6 | 5 | 2 | 7 |

7 | 3 | 8 | 4 | 2 | 8 | 9 | 5 | 8 | 6 |

7 | 4 | 5 | 6 | 9 | 6 | 4 | 4 | 6 | 6 |

(i) Find how many students obtained marks equal to or more than 7?

(ii) How many students obtained marks below 4?

#### Answer:

Frequency distribution of the given marks in Mathematics:

(i) Number of students who have obtained marks equal to or more than 7

= frequency of 7 + frequency of 8 + frequency of 9

= 5 + 4 + 3 = 12

(ii) Numbers of students who have scored below 4

= Frequency of 1 + frequency of 2 + frequency of 3

= 2 + 3 + 3 = 8

#### Page No 21.6:

#### Question 12:

Following is the choice of sweets of 30 students of class VI: Ladoo, Barfi, Ladoo, Jalebi, Ladoo, Rasgulla, Jalebi, Ladoo, Barfi, Rasgulla, Ladoo, Jalebi, Jalebi, Rasgulla, Ladoo, Rasgulla, Jalebi, Ladoo, Rasgulla, Ladoo, Rasgulla, Jalebi, Ladoo, Rasgulla, Ladoo, Ladoo, Barfi, Rasgulla Rasgulla, Ladoo.

(i) Arrange the name of sweets in a table using tally marks.

(ii) Which sweet is preferred by most of the students.

#### Answer:

(i)Frequency distribution of the given sweets:

(ii) The frequency of Ladoo is 12 i.e. maximum

∴ Ladoo is the sweet that is preferred by most of the students.

View NCERT Solutions for all chapters of Class 6