A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

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?

How is the moon similar to a dollar?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

who is silent in the parliament?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

What work can one never finish?