In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

Can you identify the direction in which this bus is moving; left or right?

Hint: The bus is moving on the roads of London.

Which is the correct shadow of the bird?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

Find the next number in the sequence

5 12 24 36 ?

What does this Rebus Picture means ?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?