A man, a woman and a boy can complete a job in 3, 4 and 12 days respectively. How many boys must assist 1 man and 1 woman to complete the job in 1/4th of a day?

• one day work of man=1/3
  one day work of women=1/4
  one day work of boy=1/12
  total one day work of man+woman=1/3+1/4=7/12
  then work done by man+woman in 1/4th of the day=7/12*1/4=7/48
  work left=41/48
  boy's 1/4th day work=1/12*1/4=1/48
  now, 41/48 work has to be done by x boys
  so x/(41/48)=1/(1/48)
  so x=41
• 11 years agoHelpfull: Yes(27) No(0)
• 41 boys is the answer
• 11 years agoHelpfull: Yes(8) No(2)
• lcm of (3,4,12)=12=total work
  man's 1day work=12/3=4
  womans 1 day work=12/4=3
  boys 1 day work=12=12=1
  now to complete work in 1 day total unit of work to be done in 1 day=12; therefore to complete in 1/4th day total work done must be 12*4=48 units.
  now in 1 day man & woman work (4+3)units.
  each boy does 1 unit work per day. so no of boys required to complete 48 units of work in 1 day= (48-7)/1=41 boys
  
• 11 years agoHelpfull: Yes(7) No(2)
• 41 is correct
• 11 years agoHelpfull: Yes(1) No(0)
• how you got that
• 11 years agoHelpfull: Yes(0) No(3)
• ans :
  7/4
  
• 11 years agoHelpfull: Yes(0) No(12)
• 41 boys is correct ans
  
• 11 years agoHelpfull: Yes(0) No(1)