WHAT I GET IS P(positive)=p+q(N-1)
P(murderer given positive)/P(positive given murderer)=P(meruderer)/P(positive)
but this gives me P(murderer given positive)=p/[N[p+(N−1)q]] therefore an extra factor of N!
Guys my question should be easy but I cannot understand how it works, here is how it goes.
A murder case involves the death of a guest at a large party in a country house. The police are certain that there is only one murderer who is among the N = 100 remaining people in the house. However...