I guess I should put my tuition money to work...
Statistical probability of 2 mafia in one roomAssuming:
-3 mafia out of 12 [townie lynched]
-4 randomly selected rooms
-3 people assigned to a room (making a total of 12 possible "spots")
Mafia #1
-Goes to random room
-0% chance of being place with other mafia (at start)
Mafia #2
-Goes to one of 11 "spots"
-Mafia occupies room with two remaining "spots"
-There is a 2/11 chance of being placed with mafia #1
-If Mafia #2 doesn't get matched with Mafia #1, he will occupy a second room
[Keep in mind, mafia now occupy 2 of 4 rooms or 50%]
Mafia #3
-Goes to one of 10 "spots"
-Mafia occupies rooms with 4 remaining "spots"
-There is a 4/10 chance of being placed with Mafia #1 or Mafia #2
So we take the aggregate probability (in order for simplicity)......
-2/11 chance of match with #2 = 18%
-4/10 chance of match with #3 = 40%
This means that #2 has an 82% chance of failing to match rooms with #1.
Let's assume #2 fails to match:
For mafia #3, we want to take a 60% chance out of this 82% to calculate the chance of both failing, which comes out to [.6*.82] = 49% chance
This means there is a 51% chance the mafia would be paired together randomly.In order to calculate the odds of all 3 being in the same room, we want to apply the same process...
Mafia #1
-Produces no odds, sets up probability chain
Mafia #2
-Has a 2/11 chance of joining #1 in his room. (two of eleven spots)
Mafia #3
-Has a 1/10 chance of joining #1 and #2 in his room. (one of ten spots)
Mafia #2 has a 18% chance of joining
Mafia #3 has a 10% chance of joining
To find the probability of success we multiply the chances: .18 * .1 = 1.8%
There is a 1.8% chance that 3 mafia will be placed in the same room.