Question

A bag of 10kg of rice costs Rs 185. What will be the cost of 8kg of rice?

Answer 1

Hint: Start by finding out the rate or cost of each kg or 1 kg of rice. Later this value or rate can be used to find any quantity of rice, which can be computed by multiplying the rate and the desired quantity. All the units of different quantities must be written correctly.

Complete step-by-step solution:
Given, cost of 10 kg rice = Rs 185
Now, we know the cost of 10 kg rice is Rs 185, so let’s try to find out how much each kg or 1 kg of rice would cost.
$ \Rightarrow $ Cost of 1 kg of rice $ = \dfrac{{185}}{{10}}$
Divide numerator by denominator,
$ \Rightarrow $ Cost of 1 kg of rice $ = 18.5$
Now that we know the rate of rice i.e. Rs. 18.50 per kg., let us compute the cost of 8 kg of rice as per the question.
The cost of 8 kg of rice will be found by the product of weight (kg) and rate per kg.
$ \Rightarrow $ Cost of 8 kg of rice $ = 18.50 \times 8$
Multiply the terms,
$ \Rightarrow $ Cost of 8 kg of rice $ = 148$

Hence, the cost of 8 kg of rice is Rs 148.

Note: Whenever we face such a type of question the key concept for solving the question is we have to go through a unitary method and go through what is given in the question. Here in this question, the amount is given at the end of the question and we have to find the cost of rice. So, we apply the unitary method to the quantity of rice, not on the amount. This is the key concept for solving unitary methods.