Page 96 - New Medley 5 Semester 2

2 Ratio and Proportion Competencies

C-4.1, C-4.2, C-4.3 , C-5.1

Ratio

We are familiar with the comparison of two things of same kind by

difference. For example, 20 kg of wheat is more than 15 kg of wheat
by 20 kg – 15 kg, i.e., 5 kg.

Here, we will learn how to compare the two given quantities by comparison

of division. The comparison of things by division is termed as ratio.

Suppose, the price of a pen is `10 and the price of a pencil is `5. We can

compare these prices as:

Price of a pencil `5 1 There is no unit
= = of ratio.
Price of a pen `10 2

1
is written as 1 : 2 in the ratio. 1 : 2 is read as 1 is to 2. The symbol
2

‘:’ is used to express a ratio.

Price of a pen `10 10 2
:
Similarly, = = = or 21
Price of a pencil `5 5 1

Note that 1 : 2 is not same as 2 : 1 because the order of terms is different.

Terms of a Ratio

In a ratio a : b, a is called the first term or antecedent and b is called

the second term or consequent.

a
  A ratio a : b can be expressed as a fraction like , where neither a
b

nor b is zero.

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