Question

One coat costs Rs $1121$.How much will $248$ such coat cost?

Answer 1

Hint: Here this question can be solved by unitary method. Unitary method is a technique in which we first find out the value of a single unit and then multiplying that unit to find necessary values.
For example: - $20$ Apples $ = Rs100$
                           $1$ Apple $ = \dfrac{{Rs100}}{{20}} = Rs5$
                           $5$ Apples $ = 5 \times Rs5 = Rs25$

Complete step-by-step answer: Cost of one coat $ = Rs1121$
Here one unit’s value is already given so we can easily find out the required value.
Cost of $248$ such coat $ = 248 \times Rs1121$
                                         $ = Rs278008$
Hence $Rs278008$ is the final answer.

Note: Be cautious when finding out a single unit value by applying unitary method that is the only step where you can get wrong. And it is a very vital step because the whole solution is built on this step.

Additional notes: -
Unitary method has two types of variations: -
1. Direct variation: - In this type of variation an increase or decrease in one quantity will cause an increase or decrease of another quantity. For example – Increase in the number of goods causes an increase in price of goods so they are directly related to each other.
2. Indirect variation: - In this type of variation an increase or decrease in one quantity will cause a decrease or increase of another quantity. For example - Increase in speed can cause decrease in the total distance which has to be covered.

Application of unitary method: - Unitary method has its practical application in many fields such as in problems of speed, distance, time and finding the cost of a material. It is used in business to find out profit and loss.