+1911 Five workers have been hired to complete a job. If one additional worker is hired, they could complete the job $8$ days earlier. If the job needs to completed $28$ days earlier, how many additional workers should be hired?
+129850 Let the time to complete the job with 5 workers = T days
So......the total man-days for the job is 5T
If one additional worker is hired, the man-days for the job is 6 (T - 8)
So....since the man-days will be the same for the job.....
5T = 6(T - 8)
5T = 6T - 48
48 = T
So the number of man-days to complete the job is 5(48) = 240
So.....to complete the job 28 days earlier
(number of workers needed) * ( 48 - 28) = 240
(number of workers needed) * (20) = 240
number of workers needed = 240 / 20 = 12
So.....(12 - 5) = 7 additional workers should be hired to complete the job 28 days earlier
