Question

If the cost of 5 kg of apples is Rs. 600, then what will be the cost of 27 kg apples?

Answer 1

Hint: In order to find the solution of this question, we should know about the concept of unitary method, that is, we will first find the value of a single unit from the given information and then we will find the necessary value by multiplying it with the single unit value. By using this concept, we can find the answer to this question.

Complete step-by-step solution -
In this question, we have been asked to find the cost of 27 kg of apples when it is given that the cost of 5 kg of apples is Rs. 600. Now, we know the concept of unitary method, that 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 or we can write it mathematically as, cost of n items = cost of 1 item $\times $ n, and the cost of 1 item = $\dfrac{\text{cost of m items}}{\text{m}}$.
Now, we have been given that 5 kg of apples cost Rs. 600. So, we can say that 1 kg of apples will cost $\dfrac{600}{5}$ = Rs. 120.
Now, we have been asked to find the cost of 27 kg of apples. So, we can say that, when 1 kg of apples costs Rs. 120, that means, 27 kg of apples will cost $120\times 27$ = Rs. 3240.
Hence, we can say that, if 5 kg of apples costs Rs. 600, then 27 kg of apples will cost Rs. 3240.

Note: We can also solve this question by directly multiplying the cost of 5 kg apples that is Rs. 600 with $\dfrac{27}{5}$ because, we have been asked to find the cost of 27 kg apples and we have been given the cost of 5 kg apples. But it can turn into confusion, if we forget the conventional method. So, it is better to use the unitary method to solve this question.