What do you get if you add 2 to 100 four times?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Who is that with a neck and no head, two arms and no hands? What is it?

Which is the correct shadow of the bird?

What number when divided in half becomes zero?

What word is pronounced the same if you take away four of its five letters?

A man died and leaves Rs.10,000 in his will. There are 6 beneficiaries- his 3 sons and their wives. The 3 wives receive Rs.3960 of which Priyanka gets Rs.100 more than Tanu and Neha gets Rs.100 more than Priyanka.
Pramod gets twice as much as his wife, Tushar gets the same as his wife, and Prashant gets 50% more than his wife.

Who is married to whom?

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 ?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?