Can You Solve This Tank Puzzle And Tell Which Tank Will Be Full First?

This Tank Puzzle is taking the Internet by storm lately. Even the most intelligent people can be seen going baffled over the right answer. Although it seems like it is a difficult one to crack because it looks like it may involve complex concepts of fluid mechanics but that’s not the case. If you have studied simple physics in your school, then you may be able to solve the puzzle easily. Look at the four tanks below and tell us which tank will be full first?

Tank Puzzle


1. Air Pressure is same on all tanks.
2. The flow rate of water pouring in Tank 1 through Tap is equal to the water going out through the opening.

Just start scratching your head and try to find the answer to this tank puzzle. Let us give you a hint that it involves a simple understanding of the Law of gravitational force. Now, you have all the assumptions and a hint from us. If you can solve this puzzle, then you can claim that you have a genius mind and if you aren’t able to solve or if you want to check your answer, then click on the ‘Show Answer’ button below.

[showhide type=”Tank” more_text=”Show Answer” less_text=”Hide Answer”]

Answer: Both Tanks 3 and 4 will fill together.



Since the gravitational acceleration is same for all the 4 tanks and the tank 3 and 4 are at same height, so they will fill at the same time. First, the water will start filling in the tank 3 till it reaches the vertical connecting tube attached to tank 4. Now, the gravitational force will come into play and the water will directly go to tank 4 till the water reaches the same level in both the tanks i.e the top level of the connecting tube. From this point, whatever water is supplied to tank 3 will be equally shared by both the tanks 3 and 4. So, they both will be full together.


Tell us the truth, did you gave the right answer to this Tank Puzzle? If yes, then share this post with your friends to see if they are smart enough to solve this puzzle.



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