- Jan 15, 2001

- 15,063

- 90

- 91

I am driving to a college campus today with a friend from work to stand in as an industry expert to talk to students about their career paths. We were talking about who would drive and naturally used rock-paper-scissors to decide. The first game was one of the best I've ever played. It went like this:

- SS
- SS
- SS
- SS
- SS
- RR
- SS
- SS
- PR (I threw paper)

It got me thinking about probability and I realized I'm not sure how to think about this problem. Granted, I never did well in statistics so I'm not surprised.

Would these be considered independent or dependent events if you want to know the probability of getting 8 ties in a row followed by a win? It seems obvious, but I started to confuse myself because, while another round is only played if the previous was a tie, the outcome of the previous doesn't change the probabilities of the same outcomes on the next throw. I may have already said the magic words to know the answer, but I'm simply not able to convince myself either way.

If they are independent, then is the probability of this happening (1/3)^8*(1/2)? If it is dependent, I have no clue how to solve it I think.

Thanks for any insight you can offer. I am going to post this on buzz as soon as I am able to come up with a solution to brag about winning this round (I won the next round as well but it was more typical. 3-4 fights before I claimed victory).