Find the number of squares in the below-given picture.

Out of three Friends John, Jacob and Jonny one of them is a king, one is a bureaucrat, and one is a Spy.

The king always tells the truth, the bureaucrat always lies, and the Spy can either lie or tell the truth.

John says: Jonny is a bureaucrat
Jacob says: John is a king
Jonny says: I am a Spy

Tell me, Who is the king, who is the bureaucrat, and who is the Spy?

Can you find out the missing number in the grid?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

What do you see in the given picture?

What is the next number in this series?

4,12,84,3612....

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?