NCERT Solutions for Class 7 Maths Chapter 8 Comparing Quantities Ex 8.2
NCERT Solutions for Class 7 Maths Chapter 8 Comparing Quantities Ex 8.2
These NCERT Solutions for Class 7 Maths Chapter 8 Comparing Quantities Ex 8.2 Questions and Answers are prepared by our highly skilled subject experts.
NCERT Solutions for Class 7 Maths Chapter 8 Comparing Quantities Exercise 8.2
Question 1.
Convert the given fractional numbers to per cents
Answer:
Question 2.
Convert the given decimal fractions to per cents.
(a) 0.65
(b) 2.1
(c) 0.02
(d) 12.35
Answer:
Question 3.
Estimate what part of the figures is shaded and hence find the per cent which is shaded.
Answer:
(ii) 3 parts out of 5 parts are shaded so,
This coloured part is 60%.
(iii) Here 3 parts out of 8 parts are shaded 3
Question 4.
Find:
(a) 15% of 250
(b) 1% of 1 hour
(c) 20% of ₹ 2500
(d) 75% of 1 kg
Answer:
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 a quantity is 600.
Let the quantity be x
Thus the required quantity is 12000.
(b) 12% of it is ₹ 1080
Let the required amount be x
The required amount = ₹ 9000
= 360 × 25 = ₹ 9000
(c) 40% of it is 500 km
Let the total quantity be x
The required quantity is 1250 km.
(d) 70% of it is 14 minutes
Let the required time be x
Thus, the required quantity is 20 minutes.
(e) 8% of a quantity is 40 litres
Let the quantity be x
The required quantity is 500 litres.
Question 6.
Convert given per cents to decimal fractions and also to fractions in simplest forms:
(a) 25%
(b) 150%
(c) 20%
(d) 5%
Answer:
Question 7.
In a city, 30% are females, 40% are males and remaining are children. What per cent are children?
Answer:
Females are 30% and males are 40%
Number of children = 100% – (30% + 40%)
= 100% – 70% = 30%
Thus, children are 30% of the population.
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 number of voters = 15,000
Part of voters who voted = 60%
Part of voters who did not vote = 100% – 60% = 40%
40% of 15000 = 40/100 × 15000
= 40 × 150 = 6000
Thus, 6000 voters did not vote.
Question 9.
Meeta saves ₹ 4000 from her salary. If this is 10% of her salary. What is her salary?
Answer:
Meeta saving = ₹ 4000
Let the salary be ₹ x
Saving = 10% of x
10% of x =4000
Meeta salary = ₹ 40,000/-
Question 10.
A local cricket team played 20 matches in one season. It won 25% of them. How many matches did they win?
Answer:
Total number of matches played = 20
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