Let X1,X2,… be a sequence of random variables from a continuous type distribution and m and n be two integers such that m<n, and 2≤n−m.

How can I show the probability that the third-order statistic of X1,…,Xm is equal to the fifth-order statistic of X1,…,Xn is 6⋅(n−5 m−3)(n m)?