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.

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

How many triangles can you count in the figure given?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

What does this mathematical rebus means ?

If you paint a brown house white it will become a white house. If the stoplight changes from red to green, then the light is green. So, if you throw a white shirt into the Red Sea, what will it become?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Why did Buffon take the goal with him after every Juventus match?

Rearrange the letters in "new door" to make one word.