A can fill a tank in 6 hours and B can fill the tank in 4 hours. if both the pipes are opened alternatively for an hour with A as the first then in how many hours will the tank b filled?

• A can fill a tank in 6 hours and B can fill the tank in 4 hours.
  A can fill 1/6 tank in 1 hours and B can fill 1/4 tank in 1 hours.
  then tank will be filled in 5 hrs when both the pipes are opened alternatively for an hour with A as the first
  as
  1/6+1/4 + 1/6+1/4+1/6 = 1 tank.
• 12 years agoHelpfull: Yes(33) No(12)
• ANSWER IS 5 hr
  LCM of 6 and 4 is 12..so the tank capacity is 12 litre.
  pipe A 12/6 =2 litre per hour .
  pipe B- 12/4=3 litre per hour.
  so alternatively it files,started by A,
  2+3+2+3+2=12 so the ans is 5
• 9 years agoHelpfull: Yes(33) No(0)
• ans is 5 hrs.
  (A+B)`s 1 hrs work=(1/6+1/4)=5/12
  (A+B)`s 2 hrs work=5*2/12=5/6
  remaining part=1-5/6=1/6
  it` time to A`s work. so, total time=2*2+1=5hrs.
• 10 years agoHelpfull: Yes(11) No(7)
• no i don know
• 10 years agoHelpfull: Yes(4) No(10)
• here asking how many times will take B to fill the tank and asking when both will fill the tank alternatively you all give this ans not required....
  how much B will take give the ans
  
• 7 years agoHelpfull: Yes(1) No(0)
• A can fill in 6 hrs and B in 4 hrs
  as it is alternatively filled first A for 1hr and then b 1 hr and again it fills A for 1 hr so like this
  A B
  1 2
  3 4
  5 6
  7 8
  
  Now B got 4hrs to fill the tank so totally it requires 8 hrs
• 9 years agoHelpfull: Yes(0) No(6)
• @rama dhevi gandu ..
• 9 years agoHelpfull: Yes(0) No(2)
• Two pipes A and B can fill a tank in 6 hours and 4 hours respectively. If they are opened on alternate hours and if pipe A is opened first, in how many hours, the tank shall be full ?
  3 hours
  5 hours
  7 hours
  10 hours
  Answer: Option B
  Explanation:
  (A+B)'s 2 hour's work when opened =
  16+14=512(A+B)′s 4 hour's work=512∗2=56Remaining work = 1−56=16Now, its A turn in 5 th hour16 work will be done by A in 1 hourTotal time = 4+1=5hours
• 7 years agoHelpfull: Yes(0) No(0)
• A=1/6
  B=1/4
  LCM=12
  2 6
  12
  3 4
  Efficiency=5
  Total 12 parts we need to fill
  First A hour
  2+3+2+3+2=12parts filled
  In 5 hours
  Ans is 5 hours
• 5 years agoHelpfull: Yes(0) No(0)