Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?

Count the number of balls in picture below:

There is something which you can be arrested for attempting but not for successfully completing.

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

What begins with T, ends with T, and has T in it?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

What does the below image rebus riddle means ?