Ncert solutions mathematics class 7 Solutions for Chapter 8 comparing quantities

Exercises in Chapter 8 comparing quantities Grade 7

Exercise 8.1

Exercise 8.2

Exercise 8.3

Questions in Exercise 8.1

Q1) Find the ratio of:

(a) Rs. 5 to 50 paise

(b) 15 kg to 210 g

(d) 30 days to 36 hours

Find the Ratio of:

₹ 5 to 50 paise

Find the Ratio of:

15 kg to 210 g

Find the Ratio of:

30 days to 36 hours

Q2) In a computer lab, there are 3 computers for every 6 students. How many computers will be needed for 24 students?

Population of Rajasthan = 570 lakhs and population of UP = 1660 lakhs. Area of Rajasthan = 3 lakh km2 and area of UP = 2 lakh km2.

How many people are there per km2 in both these States?

Q3) Population of Rajasthan = 570 lakhs and population of U.P. = 1660 lakhs. Area of Rajasthan = 3 lakh $km^2$ and area of U.P. = 2 lakh $km^2$ .

(i) How many people are there per km2 in both states?

(ii) Which state is less populated?

Population of Rajasthan = 570 lakhs and population of UP = 1660 lakhs. Area of Rajasthan = 3 lakh km2 and area of UP = 2 lakh km2.

Which State is less Populated?

Questions in Exercise 8.2

Convert the given Fractional numbers to Percent.

2/7

Q1) Convert the given fractional numbers to percent:

(a) $\frac{1}{8}$

(b) $\frac{5}{4}$

(d) $\frac{2}{7}$

Q2) Convert the given decimal fractions to percents:

(a) 0.65

(b) 2.1

(d) 12.35

Convert the given Decimal Fractional to Percent.

2.1

Q3) Estimate what part of the figures is colored and hence find the percent which is colored:

Estimate what part of the figures is colored and hence find the per cent which is colored.

Find:

15% of 250

Find:

1% of 1 hour

Q4) Find:

(a) 15% of 250

(b) 1% of 1 hour

(d) 75% of 1 kg

Find the whole Quantity if

70% of it is 14 minutes

Q5) Find the whole quantity if:

(a) 5% of it is 600

(b) 12% of it is Rs. 1080

(d) 70% of it is 14 minutes

(e) 8% of it is 40 liters

Find the whole Quantity if

40% of it is 500k km

Find the whole Quantity if

12% of it is ₹ 1080.

Find the whole Quantity if

5% of it is 600

Convert given percent to decimal fractions and also fractions in simplest forms:

25%

Convert given percent to decimal fractions and also fractions in simplest forms:

150%

Q6) Convert given percents to decimal fractions and also to fractions in simplest forms:

(a) 25%

(b) 150%

(d) 5%

Convert given percent to decimal fractions and also fractions in simplest forms:

20%

Q7) In a city, 30% are females, 40% are males and the remaining are children. What percent are children?

In a city, 30% are females, 40% are males and remaining are children. What percent are children?

Q8) 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?

Q9) Meeta saves Rs. 400 from her salary. If this is 10% of her salary. What is her salary?

Meeta saves ₹ 4000 from her salary. If this is 10% of her salary. What is her Salary?

Q10) A local cricket team played 20 matches in one season. It won 25% of them. How many matches did they win?

Questions in Exercise 8.3

Tell what is the profit or loss in the following transactions. Also find profit percent or loss per cent in each case.

A refrigerator bought for ₹ 12,000 and sold at ₹ 13,500.

Q1) Tell what is the profit or loss in the following transactions. Also find profit percent or loss percent in each case.

(a) Gardening shears bought for Rs. 250 and sold for Rs. 325.

(b) A refrigerator bought Rs. 12,000 and sold at Rs. 13,500.

(d) A skirt bought for Rs. 250 and sold at Rs. 150.

Convert each part of the Ratio to Percentage:

1:4

Convert each part of the Ratio to Percentage:

2: 3: 5

Q2) Convert each part of the ratio to percentage:

(a) 3 : 1

(b) 2 : 3 : 5

(d) 1 : 2 : 5

Q3) The population of a city decreased from 25,000 to 24,500. Find the percentage decrease.

The population of a city decreased from 25,000 to 24,500. Find the percentage Decrease.

Q4) Arun bought a car for Rs. 3,50,000. The next year, the price went up to Rs. 3,70,000. What was the percentage of the price increase?

Q5) I buy a T.V. for Rs. 10000 and sell it at a profit of 20%. How much money do I get for it?

Q6) Juhi sells a washing machine for Rs. 13500. She loses 20% in the bargain. What was the price at which she bought it?

Q7) (i) Chalk contains Calcium, Carbon, and Oxygen in the ratio 10 : 3: 12. Find the percentage of

Carbon in chalk.

(ii) If in a stick of chalk, Carbon is 3 g, what is the weight of the chalk stick?

If in a stick of chalk, carbon is 3g, what is the weight of the chalk stick?

Chalk contains calcium, carbon and oxygen in the ratio 10:3:12. Find the percentage of carbon in chalk.

Q8) Amina buys a book for Rs. 275 and sells it at a loss of 15%. How much does she sell it for?

Amina buys a book for ₹ 275 and sells it at a loss of 15%. How much does she sell it

Q9) Find the amount to be paid at the end of 3 years in each case:

(a) Principal = Rs. 1,200 at 12% p.a.

(b) Principal = Rs. 7,500 at 5% p.a.

Q10) What rate gives Rs. 280 as interest on a sum of Rs. 56,000 in 2 years?

What rate gives ₹ 280 as interest on a sum of ₹ 56,000 in 2 years?

Q11) If Meena gives an interest of Rs. 45 for one year at 9% rate p.a. What is the sum she has borrowed?

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Chapters in this book

Integers

Fractions and Decimals

Data Handling

Simple Equations

Lines and Angles

The Triangle and its properties

Congruence of Triangles

Comparing Quantities

Rational Numbers

Practical Geometry

Perimeter and Area

Algebraic Expressions

Exponents and Powers

Symmetry

Visualising Solid Shapes