What is the next number in this series?

4,12,84,3612....

I’m tall when I’m young, and I’m short when I’m old. What am I?

During which month do people sleep the least?

I have no life, but I can die. What am I?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

I left my campsite and hiked south for 3 miles. Then I turned east and hiked for 3 miles. I then turned north and hiked for 3 miles, at which time I came upon a bear inside my tent eating my food! What colour was the bear?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

What has no start, end, or centre?