Count the squares in the matchstick puzzle below?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

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?

Three people are in a room. Ronni looks at the Nile. The Nile looks at Senthil. Ronni is married but Senthil is not married. At any point, is a married person looking at an unmarried person? Yes, No or Cannot be determined.

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

If your uncle’s sister is not your aunt, what relation is she to you?

What goes up but never comes down?

Which number should replace the question mark?