Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

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?

There is something which you can be arrested for attempting but not for successfully completing.

There are forty elephants and they have forty-fore heads. How can this be possible?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

During which month do people sleep the least?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?