What does does this rebus picture means ?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Can you tell a 3D object that has just two surfaces?

Why do you find that most of the buildings are deprived of the 13th floor?

What do the following words have in common?

Assess
Banana
Dresser
Grammar
Potato
Revive
Uneven
Voodoo

I cannot talk, but I always reply when spoken to. What am I?

Two friends Smith and Andrew were talking about the bravery of their families. Smith told great stories about his courageous grandfather who fought for Britain in "World War I". Andrew told that his grandfather was so brave that in 1919 just after the war he was honoured with a bravery medal with the words "For our Courageous Soldiers In World War I" embedded into it. Smith knows that his friend is lying. How?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

What is the next number in this series?

4,12,84,3612....

The doctor prescribed you to take one pill from the bottle every half an hour. The bottle is now left with only three pills.

How long do you think you have before you run out of pills?