Theere are 5 men in group. Each man can complete a job in 35 days. One of them starts it . Starting from the second day, a man joins until the 5th day. Therefore, all the men work together. Find the total time taken to complete the job. ( in days)

Options

A. 9
B. 8
C. 10
D. 7

Answer

A

Explanation

Each man can complete `(1)/(35)` of the job/day.
Part of the job completed in the first 5 day.
`=(1)/(35)+(2)/(35)+(3)/(35)+(4)/(35)+(5)/(35)=(15)/(35)=(3)/(7)`
Remainig part `=(4)/(7)`
This will be completed by all the men working together.
Time taken to complete it
`=((4)/(7))/(5((1)/(35)))` days =4 days
Total time taken =9 days.