Why Aeroplane windows are round?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

What part of the chicken has the most feathers?

What Time Should the last watch show in the below figure?

Name a key which is hardest to turn.

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

What is the longest word in the dictionary?

I know there are two methods by using three time the same number with a plus(+) operator , you can make sum as 60.

One of them is 20+20+20.

whats the other way ?

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

Imagine you are in a room with no windows or doors. How will you get out?