NCERT Solutions for Class 8 Maths Chapter 7 Comparing Quantities Ex 7.2

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 Rs 1450 and two shirts marked at Rs 850 each?

Ans: From the given data, 

Total marked price = \[\text{Rs}(1,450\text{ }+\text{ }2850)\text{ }=\text{ Rs}\left( 1,450\text{ }+\text{ }1,700 \right)\text{ }=~\text{ Rs }3,150\]

Also, given that, Discount = 10%

Therefore, Discount
${\text{ = Rs}}{\text{.}}\left( {\dfrac{{{\text{10}}}}{{{\text{100}}}} \times {\text{3150}}} \right){\text{  =  Rs}}{\text{. 315}}$

Discount = Marked price - Sale price

Therefore, Sale price = Marked price – Discount 

∴ Sale price= Rs(3150 - 315) = Rs 2835

∴ Customer have to pay Rs. 2835.

2. The price of a TV is Rs. 13,000. 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.

Ans: For Rs. 100, tax = Rs. 12

${\text{For Rs}}{\text{.13,000; tax  =  Rs}}\left( {\dfrac{{{\text{12}}}}{{{\text{100}}}} \times {\text{13000}}} \right){\text{ =  Rs}}{\text{.1560}}$

Total amount = Cost + Sales Tax = Rs 13000 + Rs 1560 = Rs. 14560

Therefore, Vinod has to pay Rs. 14,560.

3. Arun bought a pair of skates at a sale where the discount given was 20%. If the amount he pays is Rs 1,600, find the marked price.

Ans:

Let $x$ be the marked price.

Discount percent = $\dfrac{{{\text{Discount}}}}{{{\text{Marked}}{\mkern 1mu} {\text{price}}}} \times {\text{100}}$ 

$\Rightarrow 20 = \dfrac{{{\text{Discount}}}}{x} \times 100{\text{ }}\;{\text{ }}$

$\text{Discount}=\dfrac{20}{100}\times x=\dfrac{1}{5}x\text{ }\!\!~\!\!\text{ }$

Also, Discount = Marked price - Sale price

$\text{ }\!\!~\!\!\text{ }\Rightarrow \dfrac{1}{5}x=x-\text{Rs}.1600$

$\Rightarrow x-\dfrac{1}{5}x=\text{Rs}.1600\text{ }\!\!~\!\!\text{ }$

$\Rightarrow \dfrac{4}{5}x=\text{Rs}.1600\text{ }\!\!~\!\!\text{  }\!\!~\!\!\text{ }$

$\begin{align} & x=\text{Rs}\left( 1600\times \dfrac{5}{4} \right) \\ & =\text{Rs}.\text{ }2000 \end{align}$

Therefore, the marked price is Rs 2000.

4. I purchased a hair-dryer for Rs 5,400 including 8% VAT. Find the price before VAT was added.

Ans:

Given, VAT = 8%

This implies, if the price without VAT is Rs 100, then price including VAT will be Rs 108.

Price including VAT = Rs. 108, original price = Rs. 100

When price including VAT = Rs. 5400, 

original price = ${\text{ =  Rs}}{\text{.}}\left( {\dfrac{{{\text{100}}}}{{{\text{108}}}} \times {\text{5400}}} \right){\text{ =  Rs}}{\text{.}}\,{\text{5000}}$

Therefore, price before VAT was added is Rs. 5000.

5. An article was purchased for ₹1239 including GST of 18%. Find the price of the article before GST was added?

Ans:  Let’s assume the price of the article before GST as ₹x.

Given that the article was purchased for 1239 rupees, including GST of 18%, so we can write the equation as 

x + GST = 1239    ….(1)

We know that GST is 18% of the price before GST, so

GST = 0.18x

Substituting this into (1)

x + 0.18x = 1239

1.18x = 1239

x = $\dfrac{1239}{1.18}$

x = 1050

So, the price of the article before GST was added is approximately 1050 rupees.

Conclusion

NCERT Solutions for Class 8 Math 7.2 Comparing Quantities provided by Vedantu offer comprehensive guidance for students. Understanding concepts like ratios, percentages, and discounts is crucial. It's important to focus on the methods of comparison, such as finding the percentage increase or decrease, and understanding how to solve word problems related to quantities. Previous year question papers cover various concepts like profit and loss, discounts, and simple interest. To excel in this topic, students should practice solving different types of problems and understand the underlying principles. Clear explanations provided in maths class 8 exercise 7.2 solutions help in grasping the concepts effectively. Regular practice and thorough understanding will help students tackle any question related to comparing quantities confidently.

Class 8 Maths Chapter 7: Exercises Breakdown

CBSE Class 8 Maths Chapter 7 Other Study Materials

Chapter-Specific NCERT Solutions for Class 8 Maths

Given below are the chapter-wise NCERT Solutions for Class 8 Maths. Go through these chapter-wise solutions to be thoroughly familiar with the concepts.

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