Complete the table series riddle by finding the number that can replace "??".

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

There are three boxes on a table. One of the box contains Gold and the other two are empty. A printed message contains in each box. One of the message is true and the other two are lies.

The first box says "The Gold is not here".

The Second box says "The Gold is not here".

The Third box says "The Gold is in the Second box".

Which box has the Gold?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

It is always ahead of me yet I can never see it. What is it?

No matter how little or how much you use me, you change me every month. What am I?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

I have branches, but no fruit, trunk or leaves. What am I?

What's the best place to go shopping in the ocean?