Question 1081944
<pre>
80 men can finish the job in 60 days. At the 16th day, 5 men were laid off and at the 45th day, 10 men were hired.
How many days were they delayed finishing the job.
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7+-day delay, from the other person is WRONG!!

80-MAN rate: {{{1/60}}}
1-MAN rate: {{{1/(80)(60) = 1/"4,800"}}}
75-MAN rate: {{{75(1/"4,800") = 1/64}}}
85-MAN rate: {{{85(1/"4,800") = 17/960}}}

Number of days the full crew (80 men) worked: 15 (day 1 to day 15)
Number of days 5 less, or 75 (80 - 5) men worked: 29 (day 16 to day 44)
Number of days 10 more, or 85 (75 + 10) men worked: Unknown, or T

We then get: T1(rate) + T2(rate) + T3(rate) = 1
                  {{{15(1/60) + 29(1/64) + T(17/960) = 1}}}
                                 {{{1/4 + 29/64 + 17T/960 = 1}}}
                      1(240) + 29(15) + 17T = 960 -- Multiplying by LCD, 960
                            240 + 435 + 17T = 960
                                  675 + 17T = 960
                                        17T = 960 - 675 
                                        17T = 285
Time taken by the final 85-man crew, to complete remaining fraction of job, or T = {{{285/17}}} = {{{16&13/17}}}, or about 17 days 

So, entire job took 15 + 29 + 17 = 61 days, which was 1 day over the 60-day deadline.</pre>