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Another day on the internet, another riddle for you to solve.
This time, rather than being a commuter on their phone or a bored Twitter user flicking through as they wait for their friend, you are your nation's top spy.
In this riddle by TED-Ed, you are infiltrating the evil empire's headquarters to find the control panel to switch off their death ray.
Your intelligence services tell you their headquarters is a pyramid with ten floors.
The top floor has one room, the second-top floor has two rooms, and so on and so on.
The control panel is hidden behind a painting which is on the highest floor that can satisfy the following conditions:
Each room has exactly three doors which connect to other rooms on that floor - except the control panel room which only connects to one.
There are no hallways or stairs to worry about.
There's no floor plan and you'll only have time to search one floor - so you need to choose the correct one.
Watch the full video, below and scroll down for the answer:
The answer is the 6th floor from the top.
Like us, you may have done a scribble and impetuously decided on the fifth floor - however this does not work as the room which leads the control room would have four connections.
Something you may have overlooked in your haste.
However, the 6th floor does work.
Why can't the intelligence services just tell us the floor to begin with?
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