Thread: a probability problem about chess

If the odds in favour of Boris beating Elena in a chess game are 5 to 4, what is the probability that Elena will win an upset victory in a best-of-five chess tournament?
----the answer is 7808/19683, i don't understand the chess thing basicly, i only can guess out what is the 19683, 3^9, but i don't know how to explain it. Can somebody explain me the chesses, and how to get the answer.
thanks a lot

Originally Posted by ives

If the odds in favour of Boris beating Elena in a chess game are 5 to 4, what is the probability that Elena will win an upset victory in a best-of-five chess tournament?
----the answer is 7808/19683, i don't understand the chess thing basicly, i only can guess out what is the 19683, 3^9, but i don't know how to explain it. Can somebody explain me the chesses, and how to get the answer.
thanks a lot

what's an "upset victory"?

i don't know either..........

that's the key to the answer. i think

Originally Posted by ives

that's the key to the answer. i think

not really

i think an upset victory just means the person who is least likely to win, wins.

thus you need to find the probability of Elena winning the best of 5 games, which means she wins three

so you want the probability of her winning 3 games

that should give you the answer, but don't quote me on that. as i said, i am a noob with probability

This is a binomial probability(the formula is set up below)



We want the prob of her winning at least 3 games so we want
P(3)+P(4)+P(5)







so we add all these up to get

thanks...
i haven't leaned the binomial things