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 Math Riddles

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Asked by Neha on 04 Dec 2024


An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

Asked by Neha on 13 Oct 2024

Joseph buys three kinds of chocolates for 100 rupees. The first one is priced at 5 rupees, second one at 3 rupees and third one at 0.5 rupees.

If he bought 100 chocolates in total, how many pieces do you think he bought each chocolate?

Asked by Neha on 04 Jan 2021


A man had five children. He had $100 with him to give to his children. He decided to start with the youngest child and then give $2 more than each younger child to his next elder child.

For example, if he gives $x to the youngest child, he will give $(x+2) to the next one, $[(x+2) + 2] to the next one and so on.

Can you find out how much did the youngest one receive?

Asked by Neha on 30 Sep 2024

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

 Weight of Animals

Asked by Neha on 17 Jan 2024

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

Asked by Neha on 08 Jun 2023


Can you find out which number multiplied by itself will give the output as 12345678987654321?

Asked by Neha on 27 Mar 2023

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

Asked by Neha on 16 Oct 2025

A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.

The mules is perfectly normal. So how come this be true ?

Asked by Neha on 08 May 2021


A Shopkeeper sold a few chickens to four different customers on a particular day. It was such that each customer purchased half of the remaining chickens and half the chicken more.

Can you find out how many chicken were sold by the shopkeeper on that day if we tell you that the fourth customer bought a single chicken ?

Asked by Neha on 01 Jul 2024

Hot Articles

Amazing Facts

Crossword puzzles

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