Principal in the School

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?

Principal in the School




Similar Riddles

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

Asked by Neha on 04 Apr 2024


What does man love more than life, hate more than death or mortal strife; That which contented men desire; the poor have, the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?

Asked by Neha on 15 Mar 2025

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

Asked by Neha on 19 Feb 2026


I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Asked by Neha on 23 Jan 2025

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Hourglass Time Puzzle

Asked by Neha on 30 Mar 2021

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

Asked by Neha on 11 Jun 2025


A spy was in Canada trying to steal insider information on how to set up new Maple Syrup factories in their country. He was introduced to the operations manager of the biggest factory in Canada. However, the manager was suspicious and decided to test him with a question before he trusted him. So he asked, “What would you be sure to find in the middle of Toronto?” The spy thought fast and came up with an answer for the manager. What was his answer?

Asked by Neha on 04 Jun 2025

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

Asked by Neha on 27 Dec 2020

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Asked by Neha on 21 Feb 2024


A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

Asked by Neha on 09 Apr 2024

Hot Articles

Amazing Facts

Crossword puzzles

In the 1920s, people feared that crossword puzzles would contribute to illiteracy.