Q. A, Band C can do a piece of work in 11 days, 20 days and 55 days respectively, working alone. How soon can the work be done if A is assisted by Band C on alternate days?

Option
a) 7 days
b) 8 days
c) 9 days
d) 10 days

• Ans: 8 days
  (A+B)'s 1 day's work = 1/11+1/20 = 31/220
  (A+C)'s 1 day's work = 1/11+1/55 = 6/55
  work done in 2 day's = 31/220+6/55 = 55/220 = 1/4
  1/4th work done in 2 days
  work done= 4*2 = 8 days
• 10 years agoHelpfull: Yes(17) No(0)
• b)is the right answer.
• 10 years agoHelpfull: Yes(0) No(5)
• b) 8 days
  1 day work of a n b = (1/11)+(1/20)=31/220
  1 day work of a n c =(1/11)+(1/55)=(6/55)
  then total work completed in two days =(31/220)+(6/55)=(1/4)
  there fore total work will complete in 8 days
• 9 years agoHelpfull: Yes(0) No(0)