Do You See It?

Why Aeroplane windows are round?

What word is pronounced the same if you take away four of its five letters?

I don't get anymore wetter, no matter how much rain falls on me.

Can you fill the blank with the correct number?

6 30 870 756030 _____

The two towns are exactly 100 km apart. John leaves City A driving at 30 km/hr and Jacob leaves City B half an hour later driving at 60 km/hr. Who will be closer to City A when they meet?

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

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 have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

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?