Why Aeroplane windows are round?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

Which of the below owl is odd one out?

When it is alive we sing, when it is dead we clap our hands. What is it?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

Who is that with a neck and no head, two arms and no hands? What is it?

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

who is silent in the parliament?

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.