The weight of $30$ boxes is $6$ kg. What is the weight of such $1080$ boxes?

Hint: In the question we are given the weight of $ 30 $ boxes and we have to calculate the weight of such $ 1080 $ boxes. For this we will use the unitary method. So, we will first learn some concepts of Unitary Method and then we will do our questions according to this method to get our required answer.

Complete step-by-step answer:
Using unitary method
Weight of $ 1080 $ boxes $ = $ weight of $ 1 $ box $ \times 1080 $ kg
As we have calculated above that
Weight of 1 box = $ \dfrac{5}{30} $
 $ \Rightarrow $ Weight of 1 box is $ \dfrac{1}{5} $ kg
Using this,
Weight of $ 1080 $ boxes $ = $ $ \dfrac{1}{5} $ $ \times 1080 $ kg
 $ \Rightarrow $ Weight of $ 1080 $ boxes $ = $ $ 216 $ kg
 $ \therefore $ Weight of $ 1080 $ boxes is $ 216 $ kg and that is our required answer.
So, the correct answer is “ $ 216 $ kg”.

Note: Unitary method is mainly used in our daily life. You must have usually observed supermarkets offer discounts on t-shirts, if we want to buy two t-shirts then there is a different price and if we want to buy three or four t-shirts then there is a different price. At that time we usually wish to find the price of one t-shirt. So we can see many applications of the unitary method in our day to day daily life.