A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

When it's bad luck to meet a black cat?

A father is locked up in jail. His wife has gone bankrupt. Their male child has to sell his hotel in order to gain some money. Yet their girl child does not care and is quite happy.

How can someone be so rude?

What is the centre of gravity?

What country can make you shiver?

Can you start the fire using two pieces of wood?

What is both possible and impossible at the same time?

What is harder to catch the faster you run?

What can you see in the middle of March and April that you can never see in any other month?