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?

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

Chef Andrea has to light the kitchen stoves to open her restaurant for the day. There are three stoves in the kitchen: A glass stove, a brick stove, and a wood stove. She only has one match. Which does she light up first?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

Can you count the number of quadrilaterals in the picture below?

If you can spot the hidden clock quickly, you are often those with high IQs and exceptionally keen observation skills. You excel in noticing the finest details that others might miss and can process visual information at lightning speed.

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day