Pipe A can fill a tank in 12 minutes and pipe B can fill it in 15 minutes, Pipe C can empty the tank in 6 minutes. If pipe A and B are opened for 5 minutes. And then C is also opened, then in how much time will the tank get empty?

• 4 1/2 min.
  
  5 min. filling by A & B= 5[(1/12)+(1/15)]=3/4
  time taken by C to empty 3/4 th tank=(3/4)/(1/6)=9/2 or 4 1/2 min.
• 9 years agoHelpfull: Yes(1) No(2)
• 45 min is right answer
• 9 years agoHelpfull: Yes(1) No(0)
• ans is 45 mins
  5 min. filling by A & B= 5[(1/12)+(1/15)]=3/4
  time taken by c to empty=1/12+1/15-1/6=1/60
  time taken by the tank get empty=60*3/4=45 mins
• 9 years agoHelpfull: Yes(1) No(0)
• as a and b will fill the tank 3/4th,when all d three pipes are opened the leakage will work faster,therefore,due to pipe c the tank will get emptied in 45mins.
  c-a+b=1,1/6-1/12+1/15=3/4.by solving this will get the answer.
• 8 years agoHelpfull: Yes(1) No(0)
• how 45 can you please expain @VANDIT JAIN
• 9 years agoHelpfull: Yes(0) No(0)