Comparing Quantities - Solutions 2
CBSE Class –VII Mathematics
NCERT Solutions
Chapter 8 Comparing Quantities (Ex. 8.2)
NCERT Solutions
Chapter 8 Comparing Quantities (Ex. 8.2)
Question 1. Convert the given fractional numbers to percent:
(a)
(b)
(c)
(d)
Answer: (a) = = 12.5%
(b) = 5 x 25% = 125%
(c) = = 7.5%
(d)
Question 2. Convert the given decimal fractions to percents:
(a) 0.65
(b) 2.1
(c) 0.02
(d) 12.35
Answer: (a) 0.65 = = 65%
(b) 2.1 = = 210%
(c) 0.02 = = 2%
(d) 12.35 = = 1235%
Question 3. Estimate what part of the figures is coloured and hence find the percent which is coloured:

Answer: (i) Coloured part =
Percent of coloured part = = 25%

(ii) Coloured part =
Percent of coloured part = = 60%

(iii) Coloured part =
Percent of coloured part = =
= 37.5%

Question 4. Find:
(a) 15% of 250
(b) 1% of 1 hour
(c) 20% of Rs. 2500
(d) 75% of 1 kg
Answer: (a) 15% of 250 = = 15 x 2.5 = 37.5
(b) 1% of 1 hours = 1% of 60 minutes = 1% of (60 x 60) seconds
= = 6 x 6 = 36 seconds
(c) 20% of Rs. 2500 = = 20 x 25 = Rs. 500
(d) 75% of 1 kg = 75% of 1000 g = = 750 g = 0.750 kg
Question 5. Find the whole quantity if:
(a) 5% of it is 600
(b) 12% of it is Rs. 1080
(c) 40% of it is 500 km
(d) 70% of it is 14 minutes
(e) 8% of it is 40 liters
Answer: Let the whole quantity be in given questions:
(a) 5% of = 600
= 12,000
(b) 12% of = Rs. 1080
= Rs. 9,000
(c) 40% of = 500 km
= 1,250 km
(d) 70% of = 14 minutes
= 20 minutes
(e) 8% of = 40 liters
= 500 liters
Question 6. Convert given percents to decimal fractions and also to fractions in simplest forms:
(a) 25%
(b) 150%
(c) 20%
(d) 5%
Answer:
S. No. | Percents | Fractions | Simplest form | Decimal form |
(a) | 25% | 0.25 | ||
(b) | 150% | 1.5 | ||
(c) | 20% | 0.2 | ||
(d) | 5% | 0.05 |
Question 7. In a city, 30% are females, 40% are males and remaining are children. What percent are children?
Answer: Given: Percentage of females = 30%
Percentage of males = 40%
Total percentage of females and males = 30 + 40 = 70%
Percentage of children = Total percentage – Percentage of males and females
= 100% – 70%
= 30%
Hence, 30% are children.
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: Total voters = 15,000
Percentage of voted candidates = 60%
Percentage of not voted candidates = 100% – 60% = 40%
Actual candidates, who did not vote = 40% of 15000 = = 6,000
Hence, 6,000 candidates did not vote.
Question 9. Meeta saves Rs. 400 from her salary. If this is 10% of her salary. What is her salary?
Answer: Let Meera’s salary be Rs.
Now, 10% of salary = Rs. 400
10% of = Rs. 400
4,000
Hence, Meera’s salary is Rs. 4,000.
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 matches played by cricket team = 20
Percentage of won matches = 25%
Total matches won by them = 25% of 20 = = 5
Hence, they won 5 matches.