S1 OCR Question!

Could somebody please help me out with this question?
It's question 8 on the June 2011 S1 OCR paper:

Ann, Bill, Chris and Dipak play a game with a fair cubical die. Starting with Ann they take turns, in alphabetical order, to throw the die. This process is repeated as many times as necessary until a player throws a 6. When this happens, the game stops and this player is the winner.
Find the probability that
(i) Chris wins on his first throw, [1]
(ii) Dipak wins on his second throw, [3]
(iii) Ann gets a third throw, [2]
(iv) Bill throws the die exactly three times [4]


Is this about a geometric distibution because I assumed so but couldn't work out how to answer any of the 4 parts?!

What must happen for Chris to win on his first throw?

A and B fail to get a 6 and then Chris gets a 6. What's the probability of that?

If D wins on his second throw you must have

A fails, B fails, C fails, D fails, A fails, B fails, C fails, D wins. What's the probability of that?