A can do work in 36 days, B can do work in 72 days and C can do work in 78 days. the three can take turns in working, i.e. A work on the first day, B work on the second day and C work on the third day and so on. which day will they finish the work?
a.17th
b.19th
c.54th
d.55th

• d. 55th
  
  3 day work of A,B & C=1/36+ 1/72+ 1/78= 51/936
  The work will be finished in 3*936/51=936/17= 55 days
• 11 years agoHelpfull: Yes(9) No(4)
• A B C in 3 day do= 1/36+ 1/72+ 1/78= 51/936= 17/312
  so it takes 1/(17/312)=18.35 thrice of days
  no of days 3*18=54
  in 54 days total work=18*(17/312)= 51/52
  remaining 1/52
  so another one day
  total 54+1=55
• 11 years agoHelpfull: Yes(9) No(3)
• 55 th will be correct as in 55 day A will work 19 days,B,C will work 18 days each.
  and in one day A do 1/36 of a work. similarly for B and c.
  in 19 days A will do 19/36 0f total work and again same for others
  and now by adding all u will get the result
  
• 11 years agoHelpfull: Yes(0) No(2)
• work in 3 day =1/36+1/72+1/78=17/312
  work is complete in days=3 *312/17=55.05 day
  so work is complete 55th day......
• 11 years agoHelpfull: Yes(0) No(0)