NCERT Solutions Class 8 Maths Chapter 7 Comparing Quantities Exercise 7.2

NCERT Solutions for Class 8 Maths Chapter 7 Comparing Quantities Exercise 7.2 focuses way of finding percentage in practical situations. This NCERT Solutions for Class 8 Maths Chapter 7 exercise includes real life topics such as discounts, profit and loss and simple interest. 

The NCERT Solutions provided are elaborated in a simple, step by step way based on the latest NCERT syllabus. Practicing NCERT Solutions from Exercise 7.2 gradually makes the students confident to solve percentage-based problems, and it's important to develop their overall understanding on comparing quantities.

1.0Download NCERT Solutions Class 8 Maths Chapter 7 Comparing Quantities Exercise 7.2: Free PDF

Download the free NCERT Solutions Class 8 Maths Chapter 7 Comparing Quantities Exercise 7.2 PDF with clear explanations to help you solve each question easily and score better.

2.0Key Concepts in Exercise 7.2 of Class 8 Maths Chapter 7

Exercise 7.2 introduces students to the important concept of increase and decrease in percentage a key skill used in daily financial calculations and comparative analysis. The main concepts covered in this exercise include:

• Percentage Increase and Decrease: Students learn how to calculate how much a quantity has increased or decreased and then express that change as a percentage of the original amount.
• Formula-Based Approach: The exercise uses the following standard formulas:
• $$\begin{gathered} \text{Percentage Increase}=\frac{\text{Increase}}{\text{Original Value}}\times 100 \\ \text{Percentage Decrease}=\frac{\text{Decrease}}{\text{Original Value}}\times 100 \end{gathered}$$
• Solving Real-Life Situations: The questions involve practical scenarios such as changes in prices, population growth or decline, and other day-to-day percentage-based changes.
• Strengthening Analytical Skills: Through step-by-step problem-solving, students improve their ability to think logically and apply formulas accurately.

3.0NCERT Class 8 Maths Chapter 7: Other Exercises

4.0NCERT Class 8 Maths Chapter 7 Exercise 7.2: Detailed Solutions

1. During a sale, a shop offered a discount of $10\%$ on the marked prices of all the items. What would a customer have to pay for a pair of jeans marked at ₹ 1450 and two shirts marked at ₹ 850 each? Sol. We have, Cost of pair of jeans = ₹ 1450 Cost of two shirts $=2\times 850=₹1700$ $\therefore$ Total cost $=1450+1700=₹3150$ Discount = $10\%$ Hence, selling price $=3150\left(1-\frac{10}{100}\right)$ = ₹ 2835
2. The price of a TV is ₹ 13000 . The sales tax charged on it is at the rate of $12\%$. find the amount that Vinod will have to pay if he buys it. Sol. Price of TV = ₹ 13000 Sales tax = 12% $\therefore$ Amount to be paid $=$ Price of T.V. $\left(1+\frac{12}{100}\right)$ $=13000\left(1+\frac{12}{100}\right)=₹14560$
3. Arun bought a pair of skates in a sale where the discount given was $20\%$. If the amount he paid was $₹1600$, find the marked price. Sol. Let the marked price of a pair of skates be ₹ 100 . Discount $=20\%$ of M.P. $=20\%$ of $₹100=₹20$ $\therefore$ S.P. $=$ M.P. - Discount $=₹(100-20)$ = ₹ 80 Now, when S.P. is ₹ 80, M.P. $=₹100$ When S.P. is Re 1, M.P. $=\mathrm{Rs}\frac{100}{80}$ When S.P. is ₹ 1600 , M.P. $=\mathrm{Rs}\left(\frac{100}{80}\times 1600\right)=₹2000$ Hence, the marked price of the pair of skates is ₹ 2000 .
4. I purchased a hair dryer for ₹ 5400 including 8% VAT. Find the price before VAT was added. Sol. Let the price before VAT be ₹x Price after including VAT $=₹5400$ $x+8\%$ of $x=5400$ $x+\frac{8x}{100}=5400$ $\frac{108\mathrm{x}}{100}=5400$ $x=\frac{5400\times 100}{108}=₹5000$
5. An article was purchased for ₹ 1239 including GST of $18\%$. Find the price of the article before GST was added? Sol. Price of an article with GST = Rs 1239 GST% = 18% Let the initial price of the article be Rs x GST $=18\%$ of the initial price of article So, the initial price of article + GST $=1239$ $x+18\%\times x=1239$ $x+\left(\frac{18x}{100}\right)=1239$ $\left(\frac{118x}{100}\right)=1239$ $x=1239\times \left(\frac{100}{118}\right)$ $\mathrm{x}=$ Rs 1050
6. A man got a $10\%$ increase in his salary. If his new salary is $₹1,54,000$, find his original salary. Sol. Let the salary before increment be ₹ 100 . Then, increase in salary $=₹10$ $\therefore$ Increased salary $=₹(100+10)=₹110$ If increased salary is $₹110$, original salary = ₹ 100 If increased salary is ₹ 154000 , original salary $=₹\left(\frac{100}{110}\times 154000\right)=₹140000$ Hence, the salary of the man before increment was ₹ 140000 .
7. On Sunday 845 people went to the Zoo. On Monday only 169 people went. What is the percent decrease in the people visiting the Zoo on Monday? Sol. People went to zoo on Sunday $=845$ People went to zoo on Monday $=169$ Decrease in people $=845-169=676$ $\therefore \%$ decrease $=\frac{676}{845}\times 100=80\%$
8. A shopkeeper buys 80 articles for ₹ 2400 and sells them for a profit of $16\%$. Find the selling price of one article. Sol. C.P. of 80 articles $=₹2400$ Profit $=16\%$ S.P. of 80 articles $=\left(\frac{100+\text{ Profit }\%}{100}\right)\times \mathrm{CP}$ $=₹\left(\frac{100+16}{100}\times 2400\right)=₹(116\times 24)$ = ₹ 2784 $\therefore$ S.P. of one article $=₹\left(\frac{2784}{80}\right)$ = ₹ 34.80
9. The cost of an article is ₹ 15,500 , ₹ 450 were spent on its repairs. If it is sold for a profit of $15\%$, find the selling price of the article. Sol. Cost of article $=₹15500$ Repairs $=₹450$ $\therefore$ Total cost $=$ Cost + Repairs $=₹15950$ Profit = 15% $\therefore$ Selling price $=\frac{15950(100+15)}{100}$ $=15950\left(1+\frac{15}{100}\right)$ = ₹ 18342.50
10. A VCR and a TV were bought for ₹ 8,000 each. The shopkeeper incurred a loss of $4\%$ on the VCR and earned a profit of $8\%$ on the TV. Find the gain or loss percent on the whole transaction. Sol. For VCR, we have C.P. $=₹8000$ and loss $=4\%$ $\therefore$ S.P. $=\left(\frac{100-\text{ Loss }\%}{100}\right)\times$ C.P. $=₹\left(\frac{100-4}{100}\times 8000\right)$ $=₹(96\times 80)=₹7680$ For TV, we have C.P. $=₹8000$ and profit $=8\%$ $\therefore$ S.P. $=\left(\frac{100+\text{ Gain }\%}{100}\right)\times$ C.P. $=₹\left(\frac{100+8}{100}\times 8000\right)$ $=₹(108\times 80)=₹8640$ $\therefore$ Total S.P. $=₹(7680+8640)$ = ₹ 16320 Total C.P. $=₹(8000+8000)=₹16000$ $\because$ S.P. > C.P. So, there is profit. $\therefore$ Total profit $=$ S.P. - C.P. $=₹(16320-16000)=₹320$ Hence, profit percent $=\left(\frac{\text{ Profit }}{\mathrm{CP}}\times 100\right)\%=\left(\frac{320}{16000}\times 100\right)\%$ $=2\%$
11. A milkman sold two of his buffaloes for ₹ 20,000 each. On one he made a gain of $5\%$ and on the other a loss of $10\%$. Find his overall gain or loss. Sol. For the first buffalo, we have S.P. $=₹20000$ and gain $=5\%$ $\therefore$ C.P. $=\frac{100}{100+\text{ Gain }\%}\times$ SP $\Rightarrow$ C.P. $=₹\left(\frac{100}{100+5}\times 20000\right)$ $=\left(\frac{100}{105}\times 20000\right)=₹\frac{2000000}{105}$ = ₹ 19047.62 For the second buffalo, we have S.P. $=₹20000$ and loss $=10\%$ $\therefore$ C.P. $=\frac{100}{100-\text{ Loss }\%}\times$ SP $=₹\left(\frac{100}{100-10}\times 20000\right)=₹\left(\frac{100}{90}\times 20000\right)$ $=\frac{2000000}{90}=₹22222.22$ $\therefore$ Total cost paid in buying the two buffaloes $=₹\left(\frac{2000000}{105}+\frac{2000000}{90}\right)$ $=₹2000000\times \frac{90+105}{90\times 105}$ $=\left(2000000\times \frac{195}{9450}\right)$ = ₹ 41269.84 Total S.P. $=₹(20000+20000)=₹40000$ $\therefore$ S.P. < C.P. So, there is a loss. $\therefore$ Total loss = C.P. - S.P. $=₹(41269.84-40000)=₹1269.84$

5.0Key Features and Benefits of Class 8 Maths Chapter 7 Exercise 7.2

• Simple and Clear Questions: The simple questions are structured to follow an easy structure to build a solid foundation in how to compare quantities using percentages. 
• Helps in Daily Life Maths: Students learn how to apply what they learn in real life by looking at price increases, discounts, and offers.
• Improves Problem-Solving Skills: With regular practice of this question students develop the speed, accuracy, and confidence to solve word problems based on percentages.
• Follow NCERT Guidelines: All of the questions are taken from the NCERT textbook, making it the perfect resource for school assessments and assignments.