A contractor agreeing to finish a work in 150 days, employed 75 men each working 8 hours daily. After 90 days, only 2/7 of the work was completed. Increasing the number of men by­­ ________ each working now for 10 hours daily, the work can be completed in time.

• He need total 225 workers work 10 hours daily for 60 days to complete the work.(The total working hours they already worked s 54000 hours. that is 2/7. so 1/7 will b 27000hrs. multiply it with 5 .then it wil b 135000. That means the remaining work. Then divide it with the remaining days and hours going to work. That is 60*10 =600. so 135000/600 =225 workers. 225-75 =150 more workers needed
• 12 years agoHelpfull: Yes(21) No(7)
• Answer is 150 workers
  
  total man work in 90 days is = 90*75*8==>54000 man work
  remaining work =1-2/7=5/7
  now, 2/7 work have 54000 man work
  5/7 work will have (54000*7/2)*5/7 ==> 135000 man work
  days left =60 and 10 hrs per day
  so, no. of workers = 135000/(60*10)==>225
  this is total workers.
  so, workers needed ==>225-75= 150 workers
• 9 years agoHelpfull: Yes(9) No(4)
• total days=150.
  1st 90 days 75 members working for 8 hours per day.they completes 2/7 th of work=nxt 60 days (75+x)members working for 10 hours per day to complete remaining 5/7 th of work
  (90*75*8)/(2/7)=(60*[75+x]*10)/(5/7)
  x=150
• 7 years agoHelpfull: Yes(4) No(0)
• any short cut
  
• 9 years agoHelpfull: Yes(2) No(2)
• total hrs of work for 2/7 of work is 90*75*8=54000
  similarly
  xhrs-----------5/7
  x=54000*5*7/2*7=135000hrs
  no.of men=135000/60*10 = 225 men
  225-75= 150 extra men...
• 9 years agoHelpfull: Yes(2) No(1)
• work done by 75 ppl in one day=75*8=600unit
  work done by them in 90 days=75*8*90=54000unit
  this is 2/7 of the work
  so remaining work is 5/7
  if 2/7=54000
  so 5/7=135000unit
  number of man*10 hr* 60 days=135000 unit of work
  so no of man =225
  he has 75 already so increased no of man =225-75=150
• 8 years agoHelpfull: Yes(2) No(0)
• 2/7 of the work needed 90*75*8 man-hours = 54,000 man-hours
  
  so remaining 5/7 of the work will need
  (5/2)*54,000 = 135,000 man- hours
  
  days remaining = 150 - 90 = 60
  working hours remaining = 60*10 = 600
  
  so men needed = 135,000 / 600 = 225
  
  and INCREASE in men needed = 225 - 75
  
  = 150
• 9 years agoHelpfull: Yes(1) No(1)
• Time(hrs) work men
  90 x 8 2/7 75
  60 x 10 1-2/7=5/7 ?
  
  Work increases so men will increase so fraction will be more than 1. i.e (5/7)/(2/7)=5/2
  
  Time decreases so men will increase as men and time are inversely related,so fraction will be more than 1. i.e 90 x 8/(60 x 8)
  
  The required no. of men= 5/2 x 90 x 8 / (60 x 10) x 75=225
  Therefore extra workers needed= 225-75=150(Ans)
  
• 8 years agoHelpfull: Yes(0) No(0)
• let the part of work done by one man in in one hour =x
  ∴ part of work done by one man in one day = 8x
  
  ∴ work done in 90 days by 75 employees each working 8 hours =( 90*75*8*x)=2/7
  
  ∴ x=(5.291*10^-6)
  now let contractor increased the number of employed by 'y'
  ∴ total no of employees =(75+y)
  
  ∴ in remaining 60 days work done by (75+y) employees each working 10 hours=
  (60*(75+y)*10*x) = 5/7 (remaining 1-2/7 work)
  putting value of x and solving gives y=150
  
• 8 years agoHelpfull: Yes(0) No(0)