You are standing next to three switches. You know these switches belong to three bulbs in a room behind a closed door – the door is tight closed, and heavy which means that it's absolutely impossible to see if any bulb is on or not. All three switches are now in position off.
You can do whatever you want with the switches and when you are finished you open the door and go into the room. While in there you have to tell which switch belongs to which bulb.
How will you do that?
Turn on the first switch and wait for a while. Turn off the first one and turn on the second. Go into the room. One bulb is shining, the second bulb is hot and the third one nothing.
See also best riddles or new riddles.cleanlogicmysterywho am I
I am a 5 letter word. Take away the first letter and I am a place's name. Take away the first two letters and I become the opposite of the 5 letter word. Who am I?
Woman, oman, man.cleanlogicwhat am I
What do you throw out when you want to use it, but take in when you don't want to use it?
What is as light as a feather but impossible to hold for several minutes?
A 400 yard long train, travelling at 30 mph, enters a 4.5 mile long tunnel.
How long will elapse between the moment the front of the train enters the tunnel and the moment the end of the train clears the tunnel?
9 minutes and 27.2727 seconds.cleanlogicmathshort
How many sides does a circle have?
Two. The inside and the outside.cleanlogicshort
When does Halloween come before Valentine's day?
In a dictionary.cleanlogic
Find words to fit the clues, all the words end in the same three letters.
_ _ _ _ _ _ Eat quickly
_ _ _ _ _ _ Unverified story
_ _ _ _ _ _ _ An outline
Devour, rumour and contour.cleanlogicshort
A hundred feet in the air, but it's back is on the ground. What is it?
A Centipede that turned upside down.cleanlogicshort
You can see me in water, but I never get wet. What am I?
You are in a cabin and it is pitch black. You have one match on you. Which do you light first, the newspaper, the lamp, the candle, or the fire?
You light the match first!