EPT
Yeah but you forgot that Blizzard's algorithm for random isn't 1/3 chance for each race, it gives you zerg 50% of the time.
Brainteaser for TeamLiquid! - Page 7
| Forum Index > General Forum |
|
Tektos
Australia1321 Posts
Yeah but you forgot that Blizzard's algorithm for random isn't 1/3 chance for each race, it gives you zerg 50% of the time. | ||
|
ixi.genocide
United States981 Posts
| ||
|
Beez
Canada18 Posts
| ||
|
EchelonTee
United States5261 Posts
pleaseee restore the original wording of the Q and put ur rebuttal in spoilers or at the bottom of the post...I enjoyed it as a Q | ||
|
Deleted User 123474
292 Posts
I spent about 20-30 minutes mulling it over in my mind, thinking, it has to be 1/3. But then why would he post it? I couldn't get behind the idea of it being anything else though, so I decided to brute force it in a slightly different way than OP. OP got Zerg at least once, so possible permutations are: ZP,ZT,ZZ; PZ,TZ,ZZ. The duplicate "ZZ" is crossed out. Now we have one "ZZ" left and the others are ZP,ZT,PZ,TZ -- meaning the chance of getting Zerg in the other game as well once already getting Zerg once has to be 1/5. Probability will stick you in the egg boiler and make you delicious. | ||
|
lyAsakura
United States1414 Posts
On June 10 2011 12:51 Beez wrote: the answer doesnt rely on knowing the race of your opponent so you can be T, P, or Z. theres no reason to even think about matchups. indeed you are correct, but everybody knows this and nobody is arguing about matchups it is simply "i play two games as random, i spawn as zerg atleast once, what's the probability of me spawning as zerg in both games" | ||
|
Zarathusta
United States114 Posts
| ||
|
Jinsho
United Kingdom3101 Posts
That is not how you should perform a serious survey. | ||
|
MangoTango
United States3670 Posts
| ||
|
LunaSaint
United Kingdom620 Posts
On June 10 2011 12:39 DragonDefonce wrote: You are treating PZ and ZP separate. That's not correct. If one of your game was played as zerg, then the probability of getting any one of the races on the other is 1/3. 1/5 would be the answer if the Bnet server tells you that you are about to play two games, and it will make it so that you play zerg at least once. In that case, PZ and ZP would be different, but in this case, they are the same. Pretty sure this is correct. The order of the games has absolutely no effect. At least one game is the same as there is a game, is it not? | ||
|
W2
United States1177 Posts
On June 10 2011 13:01 Jinsho wrote: You are taking an incredibly simple problem, obscuring it with imprecise language and presenting it to a casual populace, then defending yourself with "but three people understood it". That is not how you should perform a serious survey. Yea, if you are going to post a brainteaser, I'd rather they be fun riddles where you have to think outside the box (like those prisoner/island/village population ones). Re-visiting math isn't fun for me. Anyone got some good riddles to share? | ||
|
Tektos
Australia1321 Posts
Example of an actual brain teaser: During a visit to a mental asylum, a visitor asked the Director what the criteria is that defines if a patient should be institutionalized. "Well," said the Director, "we fill up a bathtub. Then we offer a teaspoon, a teacup, and a bucket to the patient and ask the patient to empty the bathtub." Okay, here's your test: 1. Would you use the spoon? 2. Would you use the teacup? 3. Would you use the bucket? "Oh, I understand," said the visitor. "A normal person would choose the bucket, as it is larger than the spoon." What was the director's response? Answer: + Show Spoiler + "No," answered the Director. "A normal person would pull the plug." | ||
|
freeloader625
United States180 Posts
On June 10 2011 11:51 Warpath wrote: Guys, the answer is 1/2 It's either he gets Zerg, or he doesn't. OMG I forgot where this is from.. that stupid teacher right? Someone pls link. BTW you win the thread man. | ||
|
d.o.c
United States49 Posts
EDIT: In b4 "it's already posted" several people got here first. | ||
|
Hamster1800
United States175 Posts
On June 10 2011 13:55 d.o.c wrote: If you're asking the probability the second game is zerg it's 1/3. That is not true. If I said ``I played two games as random today. In at least one of them, I was zerg. What is the probability that I was zerg in the second game?'' then the answer is 3/5, not 1/3. You changed the setup of the problem (to ``I was zerg in the first game'' instead of ``I was zerg at least once''), not the question that it is asking. | ||
|
Mailing
United States3087 Posts
"In the question's case, we are not asking the above. We are asking that given that at least 1 game was Zerg, what is the probability that both games are Zerg." "What is the probability that my other game was as Zerg as well?" These are two different things, that's not how you ask this question properly in English. | ||
|
terr13
United States298 Posts
| ||
|
lachy89
Australia264 Posts
On June 10 2011 14:08 terr13 wrote: Reading the original post, it seems perfectly clear. It says he played as Zerg at least once. What is the probability that the other game he played is as Zerg as well, it has no mention of what is first or what is second, so the answer is 1/5. He re-worded the question... The initial wording implied that one game was locked as zerg, then what is the probability that the other was zerg. Giving only three posibilities zerg/terran or protoss - therefore 1/3. | ||
|
jiabung
United States720 Posts
The OP's question is just a variation of the "brainteaser" presented above (3 choices instead of 2). The wiki article helps explain why some people might view the question as ambiguous and presents explanations for both sides. | ||
|
Rammblin Man
Canada19 Posts
What is the probability that you have to watch 2 mirror match games? This question is still ambiguous. Did your friend, who commented on the ZvZ, specifically set out searching for a ZvZ game? Did he simply pick a two-game series at random which may or may not have had a zerg in it? If its the former then yes, there are 5 possible permutations and the answer is 1/5. If its the latter, then there is no longer any relation between the first and second game and the answer is 1/3. From your wording, it seems as if your friend simply wanted to see Nestea vs TLO, and so this series very well may not have had TLO as zerg at all. Therefore the answer is 1/3. The wikipedia page for the boy/girl paradox words this reasoning rather nicely: From all families with two children, at least one of whom is a boy, a family is chosen at random. This would yield the answer of 1/3. From all families with two children, one child is selected at random, and the sex of that child is specified. This would yield an answer of 1/2. There is some further explaining of the problem on the wikipedia page, I suggest you read it. | ||
| ||
