What number when divided in half becomes zero?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

The answer I give is yes, but what I mean is no. What was the question?

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

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

What seven-letter word has hundreds of letters in it?

What begins with T, ends with T, and has T in it?

What can you see in the middle of March and April that you can never see in any other month?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?