There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

Who has married many women but was never married?

Why do we preferably have round manhole covers and not square ones?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

You can hear me, but you can't touch or see me.

What am I?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

What occurs twice in a week, once in a year but never in a day?

Why is it very easy to weigh a fish?