If a pipe can fill the tank within 6hrs.But due to leak it takes 30 min more.Now the tank is full then how much time will it take to empty the tank throught the leak.? a)78 b)56 c)66 d)59

• Suppose that it takes x hours for the pipe to fully drain the tank. Since the pipe can fill the tank completely in 6 hours, it can fill 1/6 of the tank per hour. With the hole, the tank gets filled in 6.5 hours and, so, is filled at a rate of 1/6.5 of the tank per hour.
  
  Since the pipe leaks at a rate of 1/x of the tank per hour, we see that:
  1/6 - 1/x = 1/6.5 ==> x = 1/(1/6 - 1/6.5) = 78 hours.
  
  Therefore, the answer is (A).
• 9 years agoHelpfull: Yes(10) No(2)
• ans a 78
  1/6-1/X=2/13
  1/x=1/6-2/13
  1/x=13-12/78
  x=78
• 9 years agoHelpfull: Yes(9) No(2)
• filling=6hrs
  filling+leaking=6.5hrs
  if leaking=?
  use,
  xy/x-y
  6*6.5/6-6.5
  =78
• 9 years agoHelpfull: Yes(5) No(0)
• ans is 78 hrs
  as rate of pipe filling the tank without hole is 1/6 0f tank/hr
  rate of pipe filling the tank with hole is 1/6.5 of tank /hr
  rate of leakage throgh hole=1/6-1/6.5=1/78 of tank/hr
  so time taken to empty the tank=1*78/1=78 hr
• 9 years agoHelpfull: Yes(2) No(0)
• fill= 6
  fill +leak =6(1/2) =13/2
  work done by the leak in 1 hr=1/6-2/13 = (13-12)/78
  =1/78 Ans
  
• 9 years agoHelpfull: Yes(1) No(0)
• 66
  a(1+a/x)
  a=6
  x=1/2
• 9 years agoHelpfull: Yes(0) No(1)
• 1/6+1/t=1/6.5
  then t=-78 but for outflow - is neglected
• 9 years agoHelpfull: Yes(0) No(1)
• (6*6.5) / (6-6.5) = 78 hours
• 8 years agoHelpfull: Yes(0) No(0)