Question

12 workers take 4 hours to complete a job how long 15 workers would take a complete the job

Answer 1

Hi ,

Number of workers ( x ) is

inverse proportional to working hours ( y )

x1 = 12 , y1 = 4

x2 = 15 , y2 = ?

x2 y2 = x1 y1

15 × y2 = 12 × 4

y2 = ( 12 × 4 ) /15

y2 = 16/5

y2 = 3.2 hours

I hope this helps you.

:)

Answer 2

Given that 12 workers take 4 hours to complete a job.

That means in 1 hour they do 1/4th of the job.

The job was done by 1 worker in 1 hour = 1/12 * 1/4

                                                                  = 1/48.

Therefore 15 workers would take to complete the job in:

= 48/15

= 3.2.

It would take 3.2 hours to complete the job.


Note: if the number of people goes up, the working time goes down.


Hope this helps!