It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

What goes through cities and fields, but never moves?

Its something that each of us devours,
Not just us but birds, beats, trees, and flowers,
Frets iron and nibbles steel,
Toil hard stones to meal,
Exterminates king, collapse town,
And blows the mountains down.

What came first, the chicken or the egg?

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

What work can one never finish?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day