What's the only room from which no one can enter or leave

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 ?

Can you guess the name of the month by looking the below rebus ?

Can you find the key in the picture below?

What kind of tree can you carry in your hand?

Can you find out who is the kidnapper in below Picture and why, Explain ?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?