When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

I don't get anymore wetter, no matter how much rain falls on me.

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

How many times can you subtract the number two from the number fifty?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

I know a nine-letter word having only one vowel.
Do you ?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

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

What has one letter and starts with an E?

Count the number of times the letter "F" appears in the following paragraph:

FAY FRIED FIFTY POUNDS OF
SALTED FISH AND THREE POUNDS
OF DRY FENNEL FOR DINNER FOR
FORTY MEMBERS OF HER FATHER'S FAMILY.