1. The problem statement, all variables and given/known data Let <d1,d2,d3...dN> be an odered set of samples from an exponential random variable with parameter lambda. Let <l1,l2,l3,...,lM> the same. Let Z = min<d1,d2,...,dN> --> Z is exp with parameter lambda*N Let U = min<l1,l2,...,lM> --> U is exp with parameter lambda*M 2. Relevant equations Since we can write that: p(Z > U) = M/(N+M), which is in fact, p(d1 > l1)= p(Z > l1) How can I compute the following probability: p(Z > l2), p(Z > l3),...,p(Z > lN). 3. The attempt at a solution Until now I am "approximating" this probability by assuming that: p(Z > l2) = (M-1)/((M-1)+N) and succesively, but I know it is wrong.... Thanks a lot in advance!