We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

There are two guys standing face to face in a room. On a wall, there is a clock. One of those is a prophet. He tells the other guy that he will be stabbed in the back in five minutes.

Shocked to hear that, the other guy stares at the clock. Just after the five minutes, he is stabbed on the back. Can you tell what happened?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

If we change the South-East direction into North and North-East into West and all others similarly.
Can you find out which direction will be in the place of South-West direction?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?