EXERCISE 8.2
Q 1, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Convert the given fractional numbers to percent:
(a) $\dfrac{1}{8}$
Sol :
$\dfrac{1}{8}=\dfrac{1}{8}\times 100\%$ $=\dfrac{25}{2}\%$ = 12.5%
(b) $\dfrac{5}{4}$
Sol :
$\dfrac{5}{4}=\dfrac{5}{4}\times 100\%$ = 5 × 25% = 125%
(c) $\dfrac{3}{40}$
Sol :
$\dfrac{3}{40}=\dfrac{3}{40}\times 100\%$ $=\dfrac{3}{2}\times 5\%$ $=\dfrac{15}{2}\%$ = 7.5%
(d) $\dfrac{2}{7}$
Sol :
$\dfrac{2}{7}=\dfrac{2}{7}\times 100\%$ $\dfrac{200}{7}\%$ $=28\dfrac{4}{7}\%$
Q 2, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Convert the given decimal fractions to percents:
(a) 0.65
Sol :
$=\dfrac{65}{100}\times 100\%$ = 65%
(b) 2.1
Sol :
$=\dfrac{210}{100}\times 100\%$ = 210%
(c) 0.02
Sol :
$\dfrac{2}{100}\times 100\%$ = 2%
(d) 12.35
Sol :
$=\dfrac{1235}{100}\times 100\%$ = 1235%
Q 3, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
QUESTION 3
Estimate what part of the figure is coloured and hence find the per cent which is coloured .
Sol :
(i) Here , 1 part out of 4 equal parts are shaded which represent fraction $\dfrac{1}{4}$
$\dfrac{1}{4}=\dfrac{1}{4}\times 100\%$ = 25%
(ii) Here , 3 parts out of 5 equal parts are shaded which represents the fraction $\dfrac{3}{5}$
Q 4, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Question 4:
Find:
(a) 15% of 250 (b) 1% of 1 hour
(c) 20% of Rs 2500 (d) 75% of 1 kg
Answer:
(a) 
(b) 1 hour = 60 minutes
(c) 
(d) 
Q 5, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
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 litres
Answer:
(a) 5% of x = 600
(b) 12% of x = Rs 1080
(c) 40% of x = 500 km
(d) 70% of x = 14 min
(e) 8% of x = 40 L
= 500 L
Q 6, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Question 6:
Convert given percents to decimal fractions and also to fractions in simplest forms:
(a) 25% (b) 150%
(c) 20% (d) 5%
Answer:
(a) 25% 
(b) 150% 
(c) 20% 
(d) 5% 
Q 7, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Question 7:
In a city, 30% are females, 40% are males and remaining are children. What per cent are children?
Answer:
It is given that 30% are females and 40% are males.
Children = (100 − 30 − 40) % = 30%
Q 8, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
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?
Answer:
Percentage of voters who voted = 60%
Percentage of those who did not vote = 100% − 60% = 40%
Number of people who did not vote = 40% of 15000
Therefore, 6000 people did not vote.
Q 9, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Question 9:
Meeta saves Rs 400 from her salary. If this is 10% of her salary. What is her salary?
Answer:
Let Meeta’s salary be Rs x.
Given that,
10% of x = 400
x = 400 × 10 = Rs 4000
Therefore, Meeta’s salary is Rs 4000.
Q 10, Ex 8.2 - Comparing Quantities - Chapter 8 - Maths Class 7th - NCERT
Question 10:
A local cricket team played 20 matches in one season. It won 25% of them. How many matches did they win?
Answer:
Number of games won = 25% of 20
Therefore, the team won 5 matches.
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