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NCERT Solutions for Class 7 Maths Exercise 8.2

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NCERT Solutions for Class 7 Maths Exercise 8.2 book solutions are available in PDF format for free download. These ncert book chapter wise questions and answers are very helpful for CBSE exam. CBSE recommends NCERT books and most of the questions in CBSE exam are asked from NCERT text books. Class 7 Maths chapter wise NCERT solution for Maths Book all the chapters can be downloaded from our website and myCBSEguide mobile app for free.

NCERT solutions for Maths Comparing Quantities Download as PDF

NCERT Solutions for Class 7 Maths Exercise 8.2

NCERT Solutions for Class 7 Maths Comparing Quantities

Class –VII Mathematics (Ex. 8.2)
Question 1.Convert the given fractional numbers to percent:

(a) {tex}\frac{1}{8}{/tex}

(b) {tex}\frac{5}{4}{/tex}

(c) {tex}\frac{3}{{40}}{/tex}

(d) {tex}\frac{2}{7}{/tex}

Answer:

(a) {tex}\frac{1}{8}{/tex} = {tex}\frac{1}{8} \times 100\% = \frac{{25}}{2}\% {/tex} = 12.5%

(b) {tex}\frac{5}{4}{/tex} = {tex}\frac{5}{4} \times 100\% = {/tex} 5 x 25% = 125%

(c) {tex}\frac{3}{{40}}{/tex} = {tex}\frac{3}{{40}} \times 100\% = \frac{3}{2} \times 5\% = \frac{{15}}{2}\% {/tex} = 7.5%

(d) {tex}\frac{2}{7}{/tex} = {tex}\frac{2}{7} \times 100\% = \frac{{200}}{7}\% = 28\frac{4}{7}\% {/tex}


NCERT Solutions for Class 7 Maths Exercise 8.2

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 = {tex}\frac{{65}}{{100}} \times 100\% {/tex} = 65%

(b) 0.02 = {tex}\frac{2}{{100}} \times 100\% {/tex} = 2%


NCERT Solutions for Class 7 Maths Exercise 8.2

Question 3.Estimate what part of the figures is coloured and hence find the percent which is coloured:

Answer:

(i) Coloured part = {tex}\frac{1}{4}{/tex}

{tex}\therefore {/tex} Percent of coloured part = {tex}\frac{1}{4} \times 100\% {/tex} = 25%

(ii) Coloured part = {tex}\frac{3}{5}{/tex}

{tex}\therefore {/tex} Percent of coloured part = {tex}\frac{3}{5} \times 100\% {/tex} = 60%

(iii) Coloured part = {tex}\frac{3}{8}{/tex}

{tex}\therefore {/tex} Percent of coloured part = {tex}\frac{3}{8} \times 100\% {/tex} = {tex}\frac{3}{2} \times 25\% {/tex}

= 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 = {tex}\frac{{15}}{{100}} \times 250{/tex} = 15 x 2.5 = 37.5

(b) 1% of 1 hours = 1% of 60 minutes = 1% of (60 x 60) seconds

= {tex}\frac{1}{{100}} \times 60 \times 60{/tex} = 6 x 6 = 36 seconds

(c) 20% of Rs. 2500 = {tex}\frac{{20}}{{100}} \times 2500{/tex} = 20 x 25 = Rs. 500

(d) 75% of 1 kg = 75% of 1000 g = {tex}\frac{{75}}{{100}} \times 1000{/tex} = 750 g = 0.750 kg


NCERT Solutions for Class 7 Maths Exercise 8.2

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 {tex}x{/tex} in given questions:

(a) 5% of {tex}x{/tex} = 600 {tex} \Rightarrow {/tex} {tex}\frac{5}{{100}} \times x = 600{/tex}

{tex} \Rightarrow {/tex} {tex}x = \frac{{600 \times 100}}{5}{/tex} = 12,000

(b) 12% of {tex}x{/tex} = Rs. 1080 {tex} \Rightarrow {/tex}{tex}\frac{{12}}{{100}} \times x = 1080{/tex}

{tex} \Rightarrow {/tex} {tex}x = \frac{{1080 \times 100}}{{12}}{/tex} = Rs. 9,000

(c) 40% of {tex}x{/tex} = 500 km {tex} \Rightarrow {/tex} {tex}\frac{{40}}{{100}} \times x = 500{/tex}

{tex} \Rightarrow {/tex} {tex}x = \frac{{500 \times 100}}{{40}}{/tex} = 1,250 km

(d) 70% of {tex}x{/tex} = 14 minutes {tex} \Rightarrow {/tex} {tex}\frac{{70}}{{100}} \times x = 14{/tex}

{tex} \Rightarrow {/tex} {tex}x = \frac{{14 \times 100}}{{70}}{/tex} = 20 minutes

(e) 8% of {tex}x{/tex} = 40 liters {tex} \Rightarrow {/tex} {tex}\frac{8}{{100}} \times x = 40{/tex}

{tex} \Rightarrow {/tex} {tex}x = \frac{{40 \times 100}}{8}{/tex} = 500 liters


NCERT Solutions for Class 7 Maths Exercise 8.2

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.PercentsFractionsSimplest formDecimal form
(a)25%{tex}\frac{{25}}{{100}}{/tex}{tex}\frac{1}{4}{/tex}0.25
(b)150%{tex}\frac{{150}}{{100}}{/tex}{tex}\frac{3}{2}{/tex}1.5
(c)20%{tex}\frac{{20}}{{100}}{/tex}{tex}\frac{1}{5}{/tex}0.2
(d)5%{tex}\frac{5}{{100}}{/tex}{tex}\frac{1}{{20}}{/tex}0.05

NCERT Solutions for Class 7 Maths Exercise 8.2

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.


NCERT Solutions for Class 7 Maths Exercise 8.2

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

= {tex}\frac{{40}}{{100}} \times 15000{/tex} = 6,000

Hence, 6,000 candidates did not vote.


NCERT Solutions for Class 7 Maths Exercise 8.2

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.{tex}x.{/tex}

Now, 10% of salary = Rs. 400

{tex} \Rightarrow {/tex} 10% of {tex}x{/tex} = Rs. 400

{tex} \Rightarrow {/tex} {tex}\frac{{10}}{{100}} \times x = 400{/tex}

{tex} \Rightarrow {/tex} {tex}x = \frac{{400 \times 100}}{{10}}{/tex}

{tex} \Rightarrow {/tex} {tex}x = {/tex} 4,000

Hence, Meera’s salary is Rs. 4,000.


NCERT Solutions for Class 7 Maths Exercise 8.2

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

= {tex}\frac{{25}}{{100}} \times 20{/tex}

= 5

Hence, they won 5 matches.

NCERT Solutions for Class 7 Maths Exercise 8.2

NCERT Solutions Class 7 Maths PDF (Download) Free from myCBSEguide app and myCBSEguide website. Ncert solution class 7 Maths includes text book solutions from Class 7 Maths Book . NCERT Solutions for CBSE Class 7 Maths have total 15 chapters. 7 Maths NCERT Solutions in PDF for free Download on our website. Ncert Maths class 7 solutions PDF and Maths ncert class 7 PDF solutions with latest modifications and as per the latest CBSE syllabus are only available in myCBSEguide.

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