Why Aeroplane windows are round?

A convention is held where all the big logicians are summoned. The master places a band on everyone's forehead. Now all of them can see others bands but can't see his own. Then they are told that there are different colours of bands. All the logicians sit in circle and they are further explained that a bell will ring at regular intervals. The moment when a logician knew the colour of band on his forehead, he will leave at the next bell. If anyone leaves at the wrong bell, he will be disqualified.

The master assures the logicians that the puzzle will not be impossible for anyone of them. How will the logicians manage ?

There is a certain crime, that if it is attempted, is punishable, but if it is committed, is not punishable. What is the crime?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

Can you place six X (crosses) in below board without making three in a row in any way ?

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

There is a place where if I stand up straight, I will still be considered sideways.

Identify the hidden meaning behind this picture?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

If you excel at these types of visual challenges, you may have superior observation skills, heightened perceptual abilities, and above-average IQs. Find the deer and prove how sharp your eyes are.