1. Let's say (hypothetically) there is a bullet, which can shoot through any barrier. Let's say there is also an absolutely bullet-proof armour, and nothing gets through it. What will happen, if such bullet hits such armour?
1a. The bullet will find that the armour is not a barrier because the armour will avoid the bullet.
2. Can a man drown in the fountain of eternal life?
2a. Repeatedly - Drown is not the same as die.
3. Your mission is to not accept the mission. Do you accept?
3a. No, problem solved.
4. This girl goes into the past and kills her Grandmother. Since her Grandmother is dead the girl was never born, if she was never born she never killed her grandmother and she was born.
4a. Depends if you consider your existence today dependant on your existence yesterday which obviously you don't: someone sent back in time has no existence the day before when they arrive. Therefore the existence of the girl is independant of the fact that she was born.
4b. You can't creates something from nothing, the total of the universe that the girl arrives in must be the same as it was before she arrived. As you are taking nothing from the universe she has left and adding nothing to the universe she arrives in (talk a bit about girl(a) girl(b) and grandmother(a) for ages and discuss if it's possible to have a copy of an original for a while but have only so much time to spend answering this
4c. The girls mother was born before the girl killed her grandmother, ergo sum...
5. If the temperature this morning is 0 degrees and the Weather Channel says, "it will be twice as cold tomorrow,".... What will the temperature be?
5a. Half as hot as today.
6. Answer truthfully (yes or no) to the following question: Will the next word you say be no?
6a. A proper paradox!
7. What happens if you are in a car going the speed of light and you turn your headlights on?
7a. Others have answered this very well, it depends which observer you are.
8. I conclude with this challenge:
Let the God Almighty create a stone, which he can not pick up (is not capable of lifting)!
8a. Presuming you are speaking of a Judeo-crhistian god, of course. Regardless of the meta-physical laws to which you allude the answer is yes, I seem to remember it took faith to move mountains not a god. A better question might be can a god create something that he can not destroy?