Five Riddles

Here are 5 of my favorite riddles.  Do not post the answer in the comments.  Good riddles are hard to find and once you know the answer, you can never go through the fun of solving it!

You're playing Russian roulette with a group of gangsters.  They load two bullets side by side in the chamber of a six shooter revolver.  Every pull of the trigger rotates the cylinder by one.  The gangster spins the cylinder and pulls the trigger.  You hear a click but no shot.  He hands the gun over to you.  What is the probability that the next shot will have a bullet?

You're on the top of a 200 foot building with 150 feet of rope.  Half way down there is a ledge to stand upon.  There are hooks at both the roof and the ledge of the building that you may attach your rope to.  You are free to cut or tie the rope as you see fit.  You cannot withstand a fall from any height.  How do you get down?

You have two candle wicks; each wick will burn from end to end in one hour's time.  The wicks are not evenly distributed, meaning that half of the wick may burn in 1 minute, while the second half burns in 59 minutes.  You do not know the distribution.  How can you measure 45 minutes?

There are 100 prisoners prepared for execution.  They are told that all prisoners will be lined up in a single-file line and each prisoner will be given a hat which is either blue or red.  Each prisoner is able to see every person's hat in front of him, but cannot see his own hat, or the hats of the prisoners behind him.  Starting from the back of the line, the executioner will ask each prisoner the color of his hat.  The prisoner is only allowed to answer a binary: blue or red (no variation of it).  If correct, the prisoner is set free; if incorrect, the prisoner is killed on the spot.  The prisoners are given an hour to come up with a plan.  What is the maximum number of prisoners they can guarantee to be save?  You can assume the executioner knows of the prisoners' plan and would work against them in his hat selection.

A band of pirates stumble upon a buried chest of treasure.  They need to figure out how to divide up the 200 pieces of treasure among the 5 of them.  The procedure works like this: the pirate with the highest seniority proposes a division.  If 50% or more of the pirates (including himself) agree, then that is how the gold is divided and they call it a day.  Else, that pirate is killed and the same procedure begins again with the pirate next in seniority.  No two pirates are tied in seniority.  You can assume that all pirates are rational thinkers (a rarity among pirates) and that each pirate is greedy (not so rare).  How will the gold be divided in the end?