Question

If in $5$ days, working $2$ hours a day, $10$ people can do a piece of work, then how long will $2$ people take to do the same work, working $5$ hours a day?
A. $5$ days
B. $8$ days
C. $10$ days
D. $12$ days
D. None of these

Answer 1

Hint: This given question is related to the concept of mensuration. The sub-topic of menstruation is time and work. We will try to find how much of the total work is to be done. To find the total work unit, we use the formula: 

Work unit = Number of men doing the work $ \times $ Number of hours $ \times $ Number of days, then find the number of days.

Complete step by step solution:
We are given that $10$ people working $2$ hours per day can do a piece of work in $5$ days.
The total work done is $ = 10 \times 2 \times 5 = 100$
We can conclude that $10$ people working at $2$ hours per day can do $100$ units of work in $5$ days.
Therefore, the number of days required by $2$ people, working at $5$ hours per day $ = \dfrac{{100}}{{2 \times 5}} = 10$
So, $2$ people working at $5$ hours per day can do the same piece of work in $10$ days.

So, the correct answer is Option (C).

Note: The given question was an easy one. Whenever such types of questions appear then, first try to find out the total amount of work units, here $10$ people working at $2$ hours per day could do the work in $5$ days, so using this information we could easily find out the amount of work done. Students can practice similar questions for more clarity and better understanding.