What is the next number in this series?

4,12,84,3612....

Buy me, smell me or deliver me, I do not change.

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 ?

A horse was tied to a rope 5 meters long and the horses food was 15 meters away from the horse. How did the horse reach the food?

You are offered an opportunity to win a fortune. There are 100 precious black stones and 100 unworthy white stones. There are two different sacks labelled as "Heads" and "Tails". You can distribute the stones as you wish. Then a coin will be flipped. Then you will have to choose a stone from the corresponding sack. If you pick up a black stone, all the fortune of black stones is yours but if you pick up white, you get nothing.

How will you distribute the stones so that you can maximize your chances of winning?

What has many teeth, but cannot bite?

If eleven plus two equals one, what does nine plus five equal?

Which is the correct shadow of the bird?

What's a single-digit number with no value?

Which number should replace the question mark?