Question

The cost of $15$ kilograms of Iron is $Rs\,750$. What will be the cost of $36$ kilograms of Iron of the same quality?

Answer 1

Hint: To answer these types of questions, then you need to be clear with the language. Unless and until you understand the question clearly, you will not be able to come up with a solution. In the question, we are given a word problem in which we are provided with the cost of fifteen kilograms of iron and are required to find the cost of $36$ kilograms of iron of the same quality.

Complete step by step solution:
Here, we are given the cost of $15$ kilograms of iron as $Rs\,750$.
We have to find the cost of $36$ kilograms of iron of the same quality. So, we will use the unitary method to first find the cost per kilogram and then multiply it with a certain number to find the cost of $36$ kilograms of iron.
So, the cost of $15$ kilograms of iron $ = Rs\,750$
Now, we find the cost of one dozen eggs by dividing the cost of $15$ kilograms of iron by $15$. So, we get,
The cost of $1$ dozen of eggs$ = Rs\,\dfrac{{750}}{{15}}$.
Cancelling common factors in numerator and denominator, we get,
$ = Rs\,50$
Now, we have to find the cost of $36$ kilograms of iron.
$\Rightarrow 36 \times 50 =1800$
Therefore, the cost of $36$ kilograms of Iron of the same quality is $ Rs.\,1800$.

Note:
The above-mentioned method can be remembered as a complete process for solving these types of questions. Be careful with the language while attending these types of questions, because there are many questions which may confuse you with the tricky and typical language. These types of questions are easy to solve when you are writing an exam as it takes less time to solve when you are thorough with this concept and have practised ample amount of questions. Unitary method involves first calculating the cost of one kilogram and then multiplying or dividing by a suitable number to get to the required answer.