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?

Can you make four (4) nines (9) equal 100?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

What is full of holes but still holds water?

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

What occurs twice in a week, once in a year but never in a day?

Replace the question mark with the correct number below.