Replace the question mark with the correct number below.

How can you tell a raw egg from a hard-boiled egg?

Can you find the 09 errors in the picture below?

Why do you find that most of the buildings are deprived of the 13th floor?

What work can one never finish?

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.

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

All of you like to eat me. I am a five-lettered word. Remove the first two and I turn into an infamous animal. Remove just the first and I become a heinous crime. Remove the first and the last and you can groove on me.

Can you guess who am I?

How can a man go eight days without sleep?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?