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Question 205843: In doing a project, a group of workers can complete the work in a certain number of days. If they are 12 more workers, the job will be completed 3 days sooner. If there are 6 workers less, the job will be delayed by 2 days. Find the number of workers and days required originally.
Answer by scott8148(6628)   (Show Source):
You can put this solution on YOUR website! it takes a certain number of worker-days (like man-hours) to complete the project ___ w * d
"If they are 12 more workers, the job will be completed 3 days sooner"
___ w * d = (w + 12) * (d - 3)
___ wd = wd - 3w + 12d - 36 ___ 3w + 36 = 12d ___ w + 12 = 4d
"If there are 6 workers less, the job will be delayed by 2 days"
___ w * d = (w - 6) * (d + 2)
___ wd = wd + 2w - 6d - 12 ___ 6d + 12 = 2w ___ 3d + 6 = w
substituting ___ (3d + 6) + 12 = 4d ___ 18 = d
substituting ___ 3(18) + 6 = w ___ 60 = w
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