It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Can you place six X (crosses) in below board without making three in a row in any way ?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

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?

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

What has 13 hearts but no other organs?

Which alphabet letter is a question?

A man died, leaving $10,000,000 for his widow, 5 sons and 4 daughters. Each daughter received an equal amount, each son received twice as much as a daughter, and the widow received three times as much as a son.

How much did the widow receive?