Class 6 Chapter 12 | Ratio And Proportions Exercise 12.1 | Free NCERT Maths Solutions

Introduction:

For comparing quantities of the same type, we commonly use the method of taking difference between the quantities.

In many situations, a more meaningful comparison between quantities is made by using division, i.e. by seeing how many times one quantity is to the other quantity. This method is known as comparison by ratio.

We denote ratio using symbol ‘:’

For example, Isha’s weight is 25 kg and her father’s weight is 75 kg. We say that Isha’s father’s weight and Isha’s weight are in the ratio 3:1.

For comparison by ratio, the two quantities must be in the same unit. If they are not, they should be expressed in the same unit before the ratio is taken.

The same ratio may occur in different situations.

Note that the ratio 3:2 is different from 2:3.Thus the order in which quantities are taken to express their ratio is important.

A ratio may be treated as a fraction, thus the ratio 10:3 may be treated as 10/3.