Two taps are running continuously to fill a tank. The first tap could have filled it in 5 hours by itself and the second one by itself could have filled it in 20 hours. But the operator failed to realize that there was a leak in the tank from the beginning which caused a delay of one hour in the filling of the tank. Find the time in which the leak would empty a filled tank?
option
a)15
b) 20
c) 25
d) 40

• in 1hr 1st tank can fill 1/5 and 2nd tap can fill 1/20
  so, both can fill (1/5 +1/20)=1/4 in 1 hr .hence required time =4hr but total time taken due to leak=5hr. so 2tap+leak can fill in 1 hr=1/5. hence leak can fill in 1 hr=(1/4-1/5)=1/20 so it can empty filled tank in 20 hr
  
• 11 years agoHelpfull: Yes(65) No(2)
• efficiency of first tap=100/5=20%
  efficiency of second tap=100/20=5%
  if both the taps were open they would have filled the tank in=100/(20+5)=4hrs
  bt due to leakage delay the tank is filled in 1hr more that is 5hrs total.
  so we have 100/(25-x)=5hrs we get x=5%,so leakage efficiency =5%,therefore total time needed to empty tank by leakage =100/5=20hrs.
• 11 years agoHelpfull: Yes(12) No(0)
• During 1st hour
  1st tank can fill 1/5 and
  2nd tap can fill 1/20
  both can fill in 1st hour (1/5 +1/20)=1/4
  let leakage pipe can empty the tank in x hours
  so reqd equn : 1/4-1/x = 1/5 => x = 20hrs
• 11 years agoHelpfull: Yes(8) No(1)
• 1/4 empty in 1 hour due to leak
  thus time required for full empty is 20 hours
• 11 years agoHelpfull: Yes(3) No(4)
• During 1st hour
  1st tank can fill 1/5 and
  2nd tap can fill 1/20
  both can fill in 1st hour (1/5 +1/20)=1/4
  let leakage pipe can empty the tank in x hours
  so reqd equn : 1/4-1/x = 1/5 => x = 20hrs
• 10 years agoHelpfull: Yes(3) No(1)
• ans is 20
  
• 11 years agoHelpfull: Yes(1) No(2)
• as a proper time the tank will be filled in 1/5+1/4= 1/4=4 hr
  but it will take 1 more hr so total time= 4+1= 5 hr
  so right time= 1/4-1/5= 20 hr ans
• 10 years agoHelpfull: Yes(1) No(0)
• 1/4-1/x=1/y
  1/y=1/5
  1/x=1/4-1/5
  x=20
  
  
• 9 years agoHelpfull: Yes(1) No(0)
• 20hrs
  as two taps can fill together in 1/5 + 1/20 =1/4i,e. 4 hrs
  opening caused a delay of 1hr so it takes 5 hrs on a whole 3 working together..
  opening can alone empty in 1/5 - 1/4 =1/20 i,e. 20hrs...
• 9 years agoHelpfull: Yes(0) No(0)
• Let Total work be 20
  Unit work by( 1st tap=4 & 2nd tap=1)
  Total unit wok by both 1st and 2nd tap=5
  The time required to fill tank=20/5=4
  But due to delay time taken=5, That implies work done by all the taps and leak=20/5=4
  So work of leak=5-4=1
  So, requird answer=20/1=20Ans
• 5 years agoHelpfull: Yes(0) No(0)