1999 Oral #2: Allergic Reactions
Source:
October 20, 2012
probability
Problem Statement
Alex, Pei-Hsin, and Edward got together before the contest to send a mailing to all the invited schools. Pei-Hsin usually just stu ffs the envelopes, but if Alex leaves the room she has to lick them as well and has a chance of dying from an allergic reaction before he gets back. Licking the glue makes Edward a bit psychotic, so if Alex leaves the room there is a chance that Edward will kill Pei-Hsin before she can start licking envelopes. Alex leaves the room and comes back to fi nd Pei-Hsin dead. What is the probability that Edward was responsible?