Unitary Method

1. Basic concept


• If the cost of 20 m cloth = Rs 1000
The cost of 1m cloth = Rs 1000÷20
                                 = Rs 50
So, the cost of 10 m cloth = Rs 50×10
                                         = Rs 500

In above example the cost of 1m cloth is first obtained and then the cost of 10m cloth is found
This method of finding one is called unitary method


In same way below example is done

• If 15 pens cost = Rs 150
The cost of 1 pen = Rs 150÷15
                             = Rs 10
The cost of 20 pens = Rs 10×20
                                 = Rs 200

 

The method in which the value of a unit quantity is first calculated to get the value of any quantity is called the unitary method

 

Try yourself


1. The cost of 4 articles is Rs 72. Find the cost of 1 article?
2. 2.25m cloth is required for 1 shirt. The cloth required for 3 shirts?
3. For 8 days a family requires Rs 320 then for 4 days the family requires?
4. A man earns Rs 400 in 10 days. How much will he earn in 28 days?
5. Weight of 8 articles is 4.8 kg. What is the weight 11 such articles?


Understanding Shapes