# NCERT Solutions For Class 6 Maths Chapter 12 Exercise 12.3

## Ncert Solutions for Class 6 Maths Chapter 12 Ratio and Proportion Exercise 12.3:-

**Exercise 12.3**Class 6 maths NCERT solutions Chapter 12 Ratio And Proportion pdf download:-

### Ncert Solution for Class 6 Maths Chapter 11 Ratio And Proportion Exercise 12.2 Tips:-

**Unitary Method**

Consider the following situations:

Two friends Reshma and Seema went to the market to purchase

notebooks. Reshma purchased 2 notebooks for ` 24. What is the

price of one notebook?

A scooter requires 2 litres of petrol to cover 80 km. How many

litres of petrol is required to cover 1 km?

These are examples of the kind of situations that we face

in our daily life. How would you solve these?

Reconsider the first example: Cost of 2 notebooks is 24.

Therefore, cost of 1 notebook = 24 2 = 12.

Now, if you were asked to find the cost of 5 such notebooks. It would be

= ` 12 × 5 = ` 60

Reconsider the second example: We want to know how many litres are

needed to travel 1 km.

For 80 km, petrol needed = 2 litres.

Therefore, to travel 1 km, petrol needed =

2

80 = 1

40 litres.

Now, if you are asked to find how many litres of petrol are required to cover

120 km?

Then petrol needed = 1

40

×120 litres = 3 litres.

**The method in which first we find the value of one unit and then the**

**value of the required number of units is known as the Unitary Method.**

**What have we discussed?**

1. For comparing quantities of the same type, we commonly use the method of

taking the difference between the quantities.

2. 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.

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.

3. 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.

4. The same ratio may occur in different situations.

5. 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.

6. A ratio may be treated as a fraction, thus the ratio 10 : 3 may be treated as10/3

7. Two ratios are equivalent if the fractions corresponding to them are equivalent. Thus,

3:2 is equivalent to 6:4 or 12:8.

8. A ratio can be expressed in its lowest form. For example, ratio 50:15 is treated as 50/15 in its lowest form50/15 =10/3. Hence, the lowest form of ratio 50 : 15 is 10 : 3.