Question

The cost of $ 2\,m $ cloth is ₹. $ 10 $ . Find the cost of $ 100 $ m cloth.
 $
 (A)\,\,400 \\
 (B)\,\,500 \\
 (C)\,\,1000 \\
 (D)\,\,1500 \\
  $

Answer 1

Hint: To find a solution to this type of problem we use a unitary method. In the unitary method we first find the cost price of $ 1m $ cloth and then multiplying it with the required number whose cost is required to find the given problem to get the correct option.

Complete step-by-step answer:
Cost of $ 2\,m $ cloth = ₹. $ 10 $
 $ \therefore $ Cost of $ 1m $ cloth = $ \dfrac{{10}}{2} $
 $ \Rightarrow \operatorname{Cos} t\,\,of\,\,1\,\,m\,\,cloth $ = ₹. $ 5 $
Therefore, cost of cloth is ₹. $ 5 $
Now, to find the cost of $ 100\,\,m $ cloth is obtained by multiplying it by cost of $ 1\,m $ cloth by $ 100 $ .
$ \Rightarrow $ Cost of $ 100 $ m cloth = $ 5 \times 100 $
=₹. $ 500 $
Therefore, from above we see that the cost price of $ 100 $ m cloth is ₹. $ 500 $ .
So, the correct answer is “Option B”.

Note: We can also find the solution of the given problem by ratio method. In this method we first let cost of $ 100 $ m cloth as ‘x’ then equating ratio of cost of $ 2m\,\,and\,\,100m $ to the ratio of length of cloth given in the problem to find value of ‘x’ and hence required solution of the problem.