HBSE 7th Class Maths Solutions Chapter 8 Comparing Quantities Ex 8.1

Haryana State Board HBSE 7th Class Maths Solutions Chapter 8 Comparing Quantities Ex 8.1 Textbook Exercise Questions and Answers.

Haryana Board 7th Class Maths Solutions Chapter 8 Comparing Quantities Exercise 8.1

Question 1.
Find ratio of:
(a) 5 Rs. to 50 paise
(b) 15 kg to 210 gm.
(c) 9 m to 27 cm
(d) 30 days to 36 hours.
Solution:
(a) Ratio between 5 Rs. to 50 paise.
= Ratio between 500 paise to 50 paise = 500 : 50 = 10 : 1.
(6) Ratio between 15 kg to 210 gm.
= 15:210 = 15 : 210 = 1: 14
(c) Ratio between 9 m to 27 cm
= 9 x 100 : 27 = 100 : 3
(d) Ratio between 30 days to 36 hours.
= Ratio between (30 x 24) hours to 36 hours
= 720 : 36 = 20 :1.

HBSE 7th Class Maths Solutions Chapter 8 Comparing Quantities Ex 8.1

Question 2.
In a computer dab there are 3 computers for every 6 students. How many computers will be needed for 24 students ?
Solution:
Let x computers are needed for 24 students.
Then the given information can be put in the following tabular form :
HBSE 7th Class Maths Solutions Chapter 8 Comparing Quantities Ex 8.1 1
It is a case of direct variation,
\(\frac{3}{6}=\frac{x}{24}\)
or x x 6 = 3 x 24
∴ x = \(\frac{3 \times 24}{6}\) =12
Hence, 12 computers are needed for 24 students.

HBSE 7th Class Maths Solutions Chapter 8 Comparing Quantities Ex 8.1

Question 3.
Population of Rajasthan = 570 lakh, Population of UP = 1660 lakhs and area of Rajasthan = 3 lakh sq. km and Area of UP = 2 lakh sq. km.
(i) How many people are there per km2, in both these States ?
(ii) Which state is less populated ?
(iii) How could you say this ?
Solution:
(i) In Rajasthan, No. of people in per sq. km = \(\frac{570}{3}\) = 190
In UP, No. of people in per sq. km = \(\frac{1660}{2}\) = 830 e.g., 190, 830
(ii) Rajasthan is less populated, density of Rajasthan = 190
(iii) Population density
= \(\frac{Total Population}{Total Area(in sq.km}\)
= Total no. of people/sq. km.

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