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?

Can it be possible to build a house that has all its four walls facing towards the South?

Who always enjoys poor health?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

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

If Rajina's daughter is my daughter's mom, who am I to Rajina?

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

In which direction should the missing arrow point?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

What number when divided in half becomes zero?