A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Can you find the key in the picture below?

I can be cracked, made, told, and played. What am I?

Which letter of the alphabet has the most water?

I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What colour was the bear?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?