Question

If 14 compositors can compose 70 pages of a book in 5 hours, how many compositors will compose 100 pages of this book in 10 hours?

1. 12
2. 10
3. 8
4. 7

Answer 1

Correct Answer - Option 2 : 10

Given:

14 compositors can compose 70 pages of a book in 5 hours

Concept:

For a given amount of work, the number of persons is inversely proportional to the number of working days, i.e. when the number of person increases then working days decrease and vice - versa. 

Working efficiency is the work done by an individual in one day and this efficiency is inversely proportional to the number of days to complete a work.

It means that a person who takes fewer days to complete a work is said to be more efficient than a person who takes more days to complete the same work.

Formula used:

(M1 × D1 × H1)/W1 = (M2 × D2 × H2)/W2

Where, M1, M2 = Number of men, D1, D2 = Number of days, H1, H2 = Number of hours, W1, W2 = Work Done

Calculation:

Here,

In the first case, M1 = 14, W1 = 70 and H1 = 5

and in the second case, W2 = 100, H2 = 10 and M2 = ?     

Now, According to the formula used

(M1 × D1 × H1)/W1 = (M2 × D2 × H2)/W2      ----(D1 an D2 will not be used as question doesn't give any data about it)

⇒ (14 × 5)/70 = (M2 × 10)/100

⇒ M₂ = (1 × 100)/10

⇒ M₂ = 10

∴ 10 compositors will compose 100 pages of this book in 10 hours.