**Chapter 8 Comparing Quantities Exercise 8.2**

Question 1.

Convert the given fractional numbers to per cents:

Solution:

Question 2.

Convert the given decimal fractions to per cents:

(а) 0.65

(b) 2.1

(c) 0.02

(d) 12.35

Solution:

Question 4.

Find:

(a) 15% of 250

(b) 1% of 1 hour

(c) 20% of ₹ 2500

(d) 75% of 1 kg

Solution:

(b) 1% of 1 hour = 1% of 60 minutes [∵ 1 h = 60 min.]

Question 5.

Find the whole quantity if

(a) 5% of it is 600

(b) 12% of it is? 1080

(c) 40% of it is 500 km

(d) 70% of it is 14 minutes

(e) 8% of it is 40 litres

Solution:

Let the required whole quantity be x.

(a) 5% of x = 600

Thus the required whole quantity is 12,000.

(b) 12% of x = ₹ 1080

Thus, the required quantity is ₹ 9,000.

(c) 40% of x = 500 km

Thus, the required quantity = 1250 km.

(d) 70% of x = 14 minutes

Thus, the required quantity = 20 minutes,

(e) 8% of x = 40 litre 8

Thus, the required quantity = 500 litres

Question 6.

Convert given per cents to decimal fractions and also to fractions in simplest forms:

(a) 25%

(b) 150%

(c) 20%

(d) 5%

Solution:

Question 7.

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

Solution:

Given: 30% are females

40% are males

Total Percentage of females and males

= 30% + 40% = 70%

∴ Percentage of children

= (100 – 70)% = 30%

Question 9.

Meena saves ₹ 400 from her salary. If this is 10% of her salary. What is her salary?

Solution:

Let Meena’s salary by ₹ x.

∴ 10% of x = ₹ 400

Thus, her salary is ₹ 4000.