Replace the question mark with the correct number.

The centre of the third figure is empty. What digit should fit inside?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

The captain of a ship was telling this interesting story: "We travelled the sea far and wide. At 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." How can that be possible?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

A dead body is found outside a multi-story multinational company. The case is reported and a homicide detective is called on the crime scene.

He looks at the body and then towards the building. From the position of the body, it is evident that the victim committed suicide. He goes to the first floor of the building and then walks in the direction of the dead body, opens the window and toss a coin in the air.

He goes to second floor and again repeats the process. He keeps doing this till he is done on all the floors. Then he returns back to the floor and tells his team that it is a murder.

How in heaven did he deduce that?

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?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

What 5-letter word typed in all capital letters can be read the same upside down?

In the image given, you can find several triangles. Can you count them all?