A tap can fill a tank in 16 min and another can empty it in 8 min. if the tank is already 1/2 full and both the taps are opend together, will the tank be filled or emplied? How will it take before the tank is either filled or empty completely?

• suppose the tank can contain 100L.then initially, it has 50L as it is half full. now 100L filled in 16 mins =>in 1 min,100/16 L is filled. also, 100L can be emptied in 8mins => in 1 min, 100/8 L is emptied. so 1min after opening the both the taps, the tank will have 50+100/16 -100/8 = 700/16 L.
  after 2 mins, the tank will have 700/16 + 100/16 - 100/8 = 600/16 L..
  similarly, after 8mins, the tank will have 0L left i.e. emptied. so,tank will be emptied after 8mins.
• 11 years agoHelpfull: Yes(3) No(0)
• 1st tap can fill with a rate of 1/16 while
  2nd tap empties it at a rate of 1/8,so it is clear that rate of emptying is more than filling,hence it will get emptied,
  now to calculate time we have...net rate of emptying=(1/8-1/16)=1/16
  to empty half tank with a rate of 1/16 we have...(1/2)/(1/16)=8minutes
• 11 years agoHelpfull: Yes(2) No(0)
• 1/8 -1/16=1/16
  16*1/2=8
• 11 years agoHelpfull: Yes(1) No(0)
• @sahaj if ur concept is right then acc. to it....it takes only 4 min to get empty.
  100/16=25/4 and 100/8=25/2
  50+25/4-25/2=75/4(1st min)
  75/4+25/4-25/2=50/4(2nd min)
  50/4+25/4-25/2=25/4(3rd min)
  25/4+25/4-25/2=0(4th min)
• 11 years agoHelpfull: Yes(0) No(0)
• @surya prakash pandey. 50+25/4 -25/2= 175/2.
  ur calculation is wrong.
• 11 years agoHelpfull: Yes(0) No(0)