Women enter hair salon with Poisson rate (l1), men enter with Poisson rate (l2), what is prob. man enters 1st?

Let T1 = the first arrival of a woman


Let T2 = the first arrival of a man





A man enters first if T2 %26lt; T1. So, we find:





Pr(T2 %26lt; T1) = l2 / (l1 + l2) (look at your notes or textbook or google to find the right formula)