NCERT Solutions for Class 7 Maths Chapter 8 Comparing Quantities Ex 8.2

Class 7 Maths NCERT Solutions Chapter 8 Comparing Quantities Ex 8.2

Ex 8.2 Class 7 Maths Question 1.
Convert the given fractional number to percents:
(a) \(\frac { 1 }{ 8 } \)
(b) \(\frac { 5 }{ 4 } \)
(c) \(\frac { 3 }{ 40 } \)
(d) \(\frac { 2 }{ 7 } \)
Solution:

Ex 8.2 Class 7 Maths Question 2.
Convert the given decimal fractions to per cents.
(a) 0.65
(b) 2.1
(c) 0.02
(d) 12.35
Solution:

Ex 8.2 Class 7 Maths Question 3.
Estimate what part of the figures is coloured and hence find the percent which is coloured.

Solution:

Ex 8.2 Class 7 Maths Question 4.
Find:
(a) 15% of 250
(b) 1% of 1 hour
(c) 20% of ₹ 2500
(d) 75% of 1 kg
Solution:

Ex 8.2 Class 7 Maths Question 5.
Find the whole quantity if
(a) 5% of it is 600
(b) 12% of it is? 1080
(c) 40% of it is 500 km
(d) 70% of it is 14 minutes
(e) 8% of it is 40 liters
Solution:

Ex 8.2 Class 7 Maths Question 6.
Convert given per cents to decimal fractions and also to fractions in simplest forms:
(a) 25%
(b) 150%
(c) 20%
(d) 5%
Solution:

Ex 8.2 Class 7 Maths Question 7.
In a city, 30% are females, 40% are males and the remaining are children. What percent are children?
Solution:
In a city,
Percentage of females = 30%
Percentage of males = 40%
Percentage of children = (100 – 30 – 40)% = 30%

Ex 8.2 Class 7 Maths Question 8.
Out of 15,000 voters in a constituency, 60% voted. Find the percentage of voters who did not vote. Can you now find how many actually did not vote?
Solution:
100% – 60% = 40% did not vote.
Number of voters who did not actually vote = 40% of 15,000
= \(\frac { 40 }{ 100 } \) × 15000
= 6000.

Ex 8.2 Class 7 Maths Question 9.
Meeta saves ₹ 400 from her salary. If this is 10% of her salary, what is her salary?
Solution:

Ex 8.2 Class 7 Maths Question 10.
A local cricket team played 20 matches in one season. It won 25% of them. How many matches did they win?
Solution:
Let the total number of matches won be P. Then,
25% of 20 = P
⇒ \(\frac { 25 }{ 100 } \) × 20 = p
⇒ 5 = p
⇒ p = 5
Hence, they won 5 matches.