What is harder to catch the faster you run?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

Name a key which is hardest to turn.

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?

Find the hidden tiger in the given optical illusion ?

A man dies of old age on his 25 birthday. How is this possible?

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?