8 people working 4 hours a day will take 15 days to complete the work.
Step-by-step explanation:
The problem can be solved using chain rule
no of people no of hours no of days
5 6 16
8 4 ?
number of days decreases when the number of people increases from 5 to 8. The decrease of number of hours from 6 to 4 increases the number of days taken for the work to get completed.
[tex]no\ of\ days\ taken\ when\ 8\ people\ work\ 4\ hours\ a\ day=16\times 6/4\times5/8\\=480/32=15[/tex]
8 people working 4 hours a day will take 15 days to complete the work.