9514 1404 393
Answer:
Explanation:
The effort required to complete a task is often estimated in terms of person·days. Amy's barn-building task takes an effort of ...
(5 workers)(9 days) = 45 worker·days
If there are only 3 workers, the time required is ...
time = (45 worker·days)/(3 workers) = 15 days
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If the barn is to be build in 7 days, the number of workers required is ...
(45 worker·days)/(7 days) = 6 3/7 workers
A minimum of 7 workers are required to build the barn in 7 days or less. (6 workers will take 7 1/2 days, so aren't enough.)