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?

What am I?

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

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

Whats the next number in the below number sequence pattern.

I throw two dice simultaneously.

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

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

Take one out and scratch my head, I am now black but once was red. What am I?

Solve the following series:
AZ, GT, MN, __, YB