10 people do the job in 10 hours = the job needs 100 man-hours
15 people do the job in 5 hours = the job needs 75 man-hours
This is contradictory. There is something amiss here. Do give clarification.
Nish Agr
(-)
(107 Points)
Replied 02 February 2011
10 people do the job in 10 hours = the job needs 100 man-hours
15 people do the job in 5 hours = the job needs 75 man-hours
This is contradictory. There is something amiss here. Do give clarification.
CA Kanchan Jha
(Finance & Accounts Executive)
(493 Points)
Replied 03 February 2011
1st case- The portion of work performed by 10 people in 1 hour = 1/10 part of work
2nd case- The portion of work done by 15 people in 1 hour = 1/5 part of work
therefore, 25 people can do the part of work in 1 hour = 1/10 + 1/5 = 3/10 par of work
so, total time taken by 25 people to complete the task = 10/3 hour = 3 hours and 20 min = 200 min
Ashok R. Shukla
(C.A., C.S.)
(108 Points)
Replied 03 February 2011
The work will be completed by 3.75 hours i.e. 3 hours and 45 minutes...