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

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

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

10+10 and 11+11 can give you the same answer.

Explain how?

There were five men at church, and it started raining while they were outside. The four that ran still got wet, but the one that was still stayed completely dry. Why did he stay dry?

What word begins and ends with an E, but has only one letter?

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?