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.

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

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?

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

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

Which city is three-fifths chick two third cat and 50% goat?

If an electric train is travelling south, then which way is the smoke going?

Different lights make me strange by changing me into different sizes. What am I?

If Rajina's daughter is my daughter's mom, who am I to Rajina?

Can you name some countries which do not have the alphabet 'A' in them?