Question 1144739
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(1)  Since 30 men can do the job in 48 hours, their rate of work is  {{{1/(30*48)}}} part of job per 1 man per hour.


(2)  After working for 20 hours, 30 men completed  {{{20/48}}} = {{{5/12}}} of the job;

     hence,  1 - {{{5/12}}} = {{{7/12}}} remained to complete.


(3)  How many time will it take for 24 remained men to complete  {{{7/12}}} of the job ?

     Divide the remaining job by {{{24/(30*48)}}} = {{{1/60}}}.  You will get

          remaining time = {{{((7/12))/((1/60))}}} = {{{(7*60)/12}}} = 35.


<U>ANSWER</U>.  35 hours after 6 men left out.
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