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 are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

Why are all black people so quick ?

What word is identified by the below rebus?

Your Your Your Your Your
Your Your Your Your Your

I’m tall when I’m young, and I’m short when I’m old. What am I?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?