There is a tank,and two pipes A and B.A can fill the tank in 25 minutes and B can empty the tank in 20 minutes.If both pipes are opened at same time.how much time required the taank can fill?

• tank will never be filled. bcz here pipe B is empting tank more faster than pipe A
• 11 years agoHelpfull: Yes(46) No(7)
• the tank will never get filled because ans is -100
• 11 years agoHelpfull: Yes(15) No(1)
• 1/25 -1/20 will be -ev so tank will never fill
• 11 years agoHelpfull: Yes(5) No(0)
• tank ill be never be filled.
  1/25-1/20="-ve"
• 11 years agoHelpfull: Yes(4) No(0)
• tank will never be filled
• 11 years agoHelpfull: Yes(4) No(0)
• the tank never filled is correct answer(B empty can take less time than fill pipeA)both are opened at same time so the tank never filled
• 11 years agoHelpfull: Yes(4) No(0)
• tank never fill bcz b is faster than a
  
• 11 years agoHelpfull: Yes(3) No(0)
• work done by both A & B=L.c.m of 25 and 20 =100
  sothat,Rate of A=100/25=4
  Rate of B=100/20=5
  As A is filling the tank and B is Emptying simultaneously then to fill the tank workdone will be the as 100 and rate=rate of A - rate of B=4-5=-1=1(take +ve)
  sothat time required to fill the tank=100/1=100min ans
• 11 years agoHelpfull: Yes(3) No(11)
• i think 100/9
• 11 years agoHelpfull: Yes(1) No(17)
• The tank will never be filled as A fills the tank in 25 mins whereas Bempties it in 20 mins so it can never be filled. i think A fills tank in 20 mins and B empties it in 25 mins so answer will be 100 mins. the question is asked wrong i suppose
• 11 years agoHelpfull: Yes(1) No(3)
• tank will nt ever been filled
• 11 years agoHelpfull: Yes(1) No(2)
• it is impossible to fill the tank .unless closing the pipe B.because rate of flow of the pipe B is more then the pipe A.
• 4 years agoHelpfull: Yes(0) No(0)
• In one minute :
  
  a fills 1/25 of the tank.
  
  b empties 1/20 of the tank.
  
  In one minute the amount of water in the tank is :
  
  1/25 - 1/20 = - 1/100 of the tank
  
  This gives - 100 minutes
  
  This means that every minute we will have a negative amount meaning no water in the tank.
  
  Therefore the tank can never get full when the two taps are opened.
  
  In essence tap B is emptying the tank faster than tap A is filling the tank.
• 4 years agoHelpfull: Yes(0) No(0)