Three of us couples are headed on a retreat next weekend. We are staying 2 nihgts and rented two cabins since the maximum number you can fit in 1 cabin is 4 people. One couple will get to spend Friday night alone in the second cabin, while another one of us couples gets to spend Saturday night alone, leaving one couple out of luck. We are going to draw straws to determine the 2 lucky couples. I told my girlfriend that we should just draw once, and the loser will be out of luck both nights, my logic being we have a 2 out of 3 chance of having one night to ourselves. But she insists on us drawing straws twice one for Friday night and one with the remaining two couples for Saturday night. Her reasoning is that we have a 1 in 3 chance the first night and a 1 in 2 chance for the second night. Which way should we go?
So you have 1/3 chance of being the unlucky couple.
So you have 2/3 chance of being the unlucky couple for the first night. If that happens, then you have 1/2 chance of being the unlucky couple for the second night also. The chances of both happening are (2/3)*(1/2)=1/3. So it’s the same.
Or you can think of it this way: whichever method you use, if each draw is fair, no couple has an advantage over others. And the results are the same - two lucky couples out of three, no more, no less. So the probability of being the lucky couple can’t be different.
The odds in both case are the same. Using your method, the odds of pulling a winning straw in the only draw are 2/3.
In your gf’s method, your odds of pulling a winning straw on the first night are 1/3, and your odds of pulling a winning straw on the second night are 1/2 * 2/3 (2/3 being the likelyhood that you’ll even participate in the second drawing). 1/3 + (1/2 * 2/3)= 2/3.
What you definitely want to avoid is having Monty Hall hold the straws.
This needs to be in MPSIMS…
No offense, since you are new you will not be subjected to toe nail pulling just yet
MPSIMS??? ummm i am sorry but not know the lingo yet
Perhaps the moderators should be the ones who decide in what category a thread belongs. Since no one but a moderator has the power to move a thread, is it really terribly helpful for a non-moderator to post “this belongs in ______”? The OP posits a probability question. I scan the list of threads in GQ and lo and behold there are a lot of probability questions. Life’s tough enough without worrying about stuff over which you have no control. Lighten up.
