AN EMPTY TANK CAN B FILLED WITH AN INLET PIPE A IN 42MIN.AFTER 12MIN ,AN OUTLET PIPE B IS OPENED WHICH CAN EMPTY THE TANK IN 30MIN.AFTER 6MIN ANOTHER INLET PIPE C OPENED INTO THE TANK ,WHICH CAN FILL IT IN 35MIN,THE TANK IS FILED IN SOME TIME LATER ,.FIND THE TOTAL TIME TO FILL THE TANK

• in first 18 minutes the tank filled will be:
  18/42-6/30=8/35
  so the amount of tank yet to be filled will be 27 parts out of 35 parts i.e. 27/18
  now we have 3 pipes 2 inlet and 1 outlet
  in 1 min they will fill:
  1/42-1/30+1/35=2/105
  hence tine required to fill 27/35 of the tank= (27/35)/(2/105)=40.5
  hence 18+40.5= 58.5
• 12 years agoHelpfull: Yes(4) No(1)
• Tank filled in fiorst 18 mins = 12/42 +6/42 - 6/30 = 3/7-1/5 =12/35 tank
  remaining tank = 1-12/35= 23/35
  with 3 pipes, tank filled in 1 minute = 1/42 +1/35-1/30 = (5+6-7)/210 =4/210 = 2/105
  
  Time taken to fill 23/35 tank = (23/35)*(105/2)= 69/2 min.
  
  total time = 69/2 + 18 = 105/2 mins = 52.5 mins
• 12 years agoHelpfull: Yes(2) No(0)