Solve the mathematical equation in the picture below.

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?

Who can jump higher than a Mountain?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

The more of this there is, the less you see. What is it?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?