CBSE NCERT Solutions for Class 7 Chapter 3

NCERT Solutions are the most important and foremost tool to look up to especially when students are preparing for school and competitive examinations. NCERT Solutions involve detailed solutions of all NCERT textbook questions.

CBSE NCERT Solutions for Class 7 Maths Chapter 3:

Question-1:

A cricketer scores the following runs in eight innings: 58, 76, 40, 35, 46, 45, 0, 100 Find the mean score.

Solution:

Number of innings = 8
Mean of score = Sum of scores
Number of innings
= (58 + 76 + 40 + 35 + 46 + 45 + 0 + 100)/ 8
=400/8
=50
Thus, the mean score is 50.

Question-2:

The marks (out of 100) obtained by a group of students in a science test are 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75.
Find the:
(i) The highest and the lowest marks obtained by the students.
(ii) Range of the marks obtained.
(iii) Mean marks obtained by the group.

Solution:

(i) Highest marks obtained by the student=95
Lowest marks obtained by the student =39
(ii) Range of marks = Highest marks – Lowest marks
= 95 – 39 =56
(iii) Mean of obtained marks = Sum of marks/Total number of marks
= (85 + 76 + 90 + 85 + 39 + 48 + 56+ 95 + 81+ 75)/10
=730/10 =73
Thus, mean marks obtained by the group of students is73.

Question-3:

The enrolment in a school during six consecutive years was as follows:
1555, 1670, 1750, 2013, 2540, 2820. Find the mean enrolment of the school for this period.

Solution:

Mean enrolment = Sum of numbers of enrolement/Total number of enrolment
= (1555 +1670 +1750+ 2013+ 2540+ 2820)/6
=12348 /6 =2058
Thus, the mean enrolment of the school is 2,058.

Question-4:

The height of 10 girls were measured in cm and the results are as follows:
135, 150, 139, 128, 151, 132, 146, 149, 143,141
(i) What is the height of the tallest girl?
(ii) What is the height of the shortest girl?
(iii) What is the range of data?
(iv) What is the mean height of the girls?
(iii) How many girls have heights more than the mean height?

Solution:

(i) The height of the tallest girl = 151cm
(ii) The height of the shortest girl = 128cm
(iii) The range of the data = Highest height – Lowest height
= 151 – 128 = 23 cm