Question

The cost of 12 quintals of soyabean is 36,000 rupees. How much will 8 quintals cost?

Answer 1

Hint: Find the cost of 1 quintal with the help of information provided. Use a unitary method to find the total amount of money required to buy 1 quintal. Then, multiply 8 quintals with the cost of one quintal to get the answer.

Complete step-by-step answer:

The unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value. In essence, this method is used to find the value of a unit from the value of a multiple, and hence the value of a multiple. For example: suppose the value of 10 pencils is Rs. 20, and we have to find the value of 50 pencils. What we have to do is, find the value of a single pencil by dividing total pencils with total rupees. In this way we will get the value of 1 pencil, then multiply this value with the total number of pencils whose cost we have to find. So, in the above example the value of 1 pencil will be Rs. 2 and therefore the value of 50 pencils will be $2\times 50=100$ rupees.

Now, in the given question, we have been provided with the cost of 12 quintals of soyabean.

$\begin{align}

  & \because \text{cost of 1 quintal= Rs}\text{. 36000} \\

 & \therefore \text{cost of 1 quintal=Rs}\text{. }\dfrac{\text{36000}}{\text{12}}\text{= Rs}\text{. 3000} \\

\end{align}$

Now, cost of 8 quintals $=$ cost of 1 quintal $\times $ total number of quintals

$\begin{align}

  & =3000\times 8 \\

 & =24000 \\

\end{align}$

Hence, the cost of 8 quintals is Rs. 24,000.

Note: We have applied a unitary method because it is the easiest approach to solve this question. Here, we were required to find the cost of one quintal of soyabean. Then, we can easily find the cost of the required number of quintals.