12 men and 4 boys togrhter can complete a piece of work in 8 days.The work done by a man in one day is double the work done by a boy in one day.if 10men and 6 boys started working together and after 3days 6 men left and 6 new boys joined,then in how many more days will thw work will be completed?
(1)51/7 days (2) 76/9days (3)43/8days (4)40/7 days (5) 73/12 days

• ans :: 7(3/10)days
  let 1 man take M days and 1 boy take B days.
  1 day work of a boy=(1/B)
  1 day work of a man = (2/B)
  12*2/B + 4/B=1/8
  so, B=28*8=224
  M=112
  3(10/112 + 6/224)=39/112 for 3 days
  work left=1-39/112=73/112
  
  this will be completed by 4 men and 12 boys.
  1 day work of 4 men and 12 boys=4/112 + 12/224=10/112
  so , 10/112 work in 1 day
  73/112 work in (112/10)*(73/112)=7(3/10)days
  
• 9 years agoHelpfull: Yes(1) No(2)