Question

If 8 meters cloth cost RS.250, find the cost of 5.8 meters of the same cloth.

Answer 1

Hint: To find the cost of $$5.8$$meter cloth, first of all, we have to find the cost of $$1$$ meter cloth by unitary method (Unitary method: A technique for solving a problem by calculating the value of the single unit first, and then finding the value for other units by multiplying the single unit value). After that, we find the required cost of$$5.8m$$ long cloth.

Complete step by step answer:
According to the question
Cost of $$8m$$cloth $$=RS.250$$
Cost of $$1m$$ cloth $$={\displaystyle \frac{250}{8}}=Rs.31.25$$
Cost of $$5.8m$$ cloth $$=5.8\times 31.25=Rs.181.25$$

Hence, the answer is$$Rs.181.25$$.

Note:
To solve these types of questions we have to understand the concepts of the unitary method and its types with proper implementation while solving the problems. The unitary method helps us in order to calculate the value of a unit quantity first and then after we figure out the value of other units.
Types of Unitary method:-
Unitary method has two types of variations.
(i) Direct Variation and
(ii) Indirect Variation
(i) Direct Variation:- It is a kind of variation in which any increase or decrease in one quantity will cause an increase and decrease in another quantity respectively. For example, purchasing some goods like eggs, the increase in the number of eggs will ultimately cost more price.
(ii) Indirect Variation:- It is a kind of variation in which any increase or decrease in one quantity will cause a Decrease and increase in another quantity respectively. For example, the increase in speed causes more distances in less time. So, we can say that on increasing the speed the traveling time will decrease.
Applications of Unitary Method:
It is used to solve many conceptual problems on the topic of time and work.
Many problems with speed, distance, and time can be solved easily with the help of these two methods.