What is the next number in this series?

4,12,84,3612....

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Which wheel of car does not rotate when you turn your car right?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

John Went to the nearby store in a Mall to buy something for her home. Below is the conversation between the two:

John: How much for the one?
Shopkeeper: It is $2
John: How much for the Eleven?
Shopkeeper: It is $4
John: How much for the Hundred?
Shopkeeper: It is $6.

What is John buying?

What can go up a chimney down, but can’t go down a chimney up?

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 ?

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

What has no start, end, or centre?