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

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

Question 1.

Find the ratio of the following :

(a) Speed of a cycle 15 km per hour to the speed of scooter 30 km per hour.

(b) 5 m to 10 km.

(c) 50 paise to Rs. 5.

Solution:

(a) Ratio of speed of cycle to speed of scooter = 15 : 30 = 1 : 2

(b) Ratio of 5 m to 10 km

⇒ Ratio of 5 m to 100000 m = 5 : 100000 = 1 : 20000

(c) Ratio of 50 paise to Rs. 5

⇒ Ratio of 50 paise to 500 paise

= 50 : 500 = 1 : 10.

Question 2.

Convert the following ratios to percentages.

(а) 3 : 4

(b) 2 : 3

Solution:

(a) Ratio = 3 : 4

Fraction = \(\frac{3}{4}\)

Percentage = \(\frac{3 \times 25}{4 \times 25}\) = \(\frac{75}{100}\) = 75%

(b) Ratio = 2 : 3

Fraction = \(\frac{2}{3}\)

Percentage = \(\frac{2}{3} \times \frac{100}{100}\) = \(\frac{200}{3} \times \frac{1}{100}\)

= 66\(\frac{2}{3}\)%.

Question 3.

72% of 25 students are good in mathematics. How many are not good in mathematics ?

Solution:

Total percent good in mathematics and not good in mathematics = 100

72 + percentage of student not good in mathematics = 100

∴ Percentage of students not good in mathematics = 100 – 72 = 28

So number of students hot good in mathematics = 28% of 25

= \(\frac{28}{100}\) × 25 = 7 students.

Question 4.

A football team won 10 matches out of the total number of matches they played. If their win percentage was 40, then how many matches did they play in all ?

Solution:

Let the total number of matches played by football team be x their win was 40%.

So, 40% of x = 10

\(\frac{40}{100}\) × x = 10

x = \(\frac{10 \times 100}{40}\) = 25

Number of played matches = 25.

Question 5.

If Chameli had Rs. 600 left after spending 75% of her money, how much did she have in the beginning ?

Solution:

Let she had Rs. x in the beginning

Chameli spent 75% of her money.

So she left 100 – 75 = 25% of her moriey.

So, 25% of x = Rs. 600

\(\frac{25}{100}\) × x = 600

x = \(\frac{600 \times 100}{25}\) = 2400

Chameli had Rs. 2400 in the beginning.

Question 6.

If 60% people in a city like cricket, 30% like football and the remaining like other games, then what percent of the people like other games ? If the total number of people are .50 lakh, find the exact number who like each type of game.

Solution:

Total percent = 100

60% people like cricket

30% people like football

remaining like other game

So 100 – (60 + 30) = 10% like other game.

Total no. of people = 50 lakh

No. of people like cricket

= 60% of 50 lakh

= \(\frac{60}{100}\) × 50 lakh = 30 lakh

No. of people like football

= 30% of 50 lakh on

= \(\frac{30}{100}\) × 50 lakh = 15 lakh

No. of people like other game

= 10% of 50 .lakh

= \(\frac{10}{100}\) × 50 lakh = 5 lakh.