**Meaning of Ratio **

The relation between two quantities (both of the same units) obtained by dividing one quantity with another is called ratio. Ratio can be denoted by using the symbol ( : ).

Table of Contents

**EXAMPLE 1 **

What is the ratio between the weight two bags of sugar of 4kg and 6kg respectively?

**Solution **

Ratio of weights of bags of sugar = 4kg/ 6kg = 2/3 = 2:3

**EXAMPLE 2 **

A pole of length 165cm is divided into two parts such that lengths are in the ration 7:8. Find the length of each part of the pole?

Total ratio = 7 + 8 = 15

First part = ^{7/}_{15 }, second part = 8/15

Length of first part = 7/15 of 165cm

= 7/15 × 165

= __7 x 11 __ = 77cm

1 x 1

Light of second part = 165cm – 77cm = 88cm

**DIRECT PROPORTION **

Examples

- A marker costs $18. Calculate the cost of 5 markers.
- A student went to the market to purchase textbooks. He purchased two textbooks for $24

- What is the price of one notebook?
- What would be the price of 5 such note

**Solution**

- If one marker = $18

5 markers = $18 x 5 = $90

- 2 textbooks = $24

1 textbook = m

2 × m = 1 x $24

2m = $24

M = $24 ÷ 2 = $12. Therefore 1 textbook = $24

(b) Since 1 textbook = $12

5 textbooks = $12 × 5 = $60

**EVALUATION **

- What is ratio?
- Find the ratio of each of the following in its lowest terms:

- 24cm: 72cm
- 425km: 750km
- 75min: 150min
- 85kg: 102kg

- A field is 50m in length and 60m in width. Find the ratio between its width and length.
- A scooter can travel 225km with 5 litres of petrol. How many litres of petrol is needed to travel 675km?

**See also**

PROBLEM ON MULTIPLICATION OF MONEY