Employed 100 workers with a contract to complete a job in 40 days. The work was completed on time as more than 100 workers were hired 35 days after the start of work. If you do not hire additional workers, how long will it take to complete the work?
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Answers
Answer:
If 5 workers complete one task in 7 days, then how many days will 7 workers take to complete the same task?
Answer 5 days
Explanation :
The total work can be finished by in 7 days if 5 men work each day.
Therefore, one man can finish the work by 7x5 = 35 days.
If this work is shared by 7 workers the work can be finished in 35/7 = 5 days.
Another method:
To complete the work, we note that when the number of workers increases, the number of days decreases.
Therefore the ratio between number of workers and number of days is in inverse proportion.
If the number of days required corresponding to 7 men is y, then we get (by reversing the second ratio)
5 : 7 :: y : 7
Hence 7y=5x7
(since the product of means equals to that of extremes)
Therefore y = 5.
Another method :
7 men finish the work in 5 days.
Therefore, in one day 7 men can complete 1/5 th portion of the work.
Hence 1 man in 1 day can complete 1/(5x7) th portion of the total work.
Therefore, in one day 7 men can finish 7x(1/(5x7)) = 1/5 th portion of the total work.
Hence they will take 5 days to finish the job