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Suppose there are nn distinct numbers x1,,xnx_1,\ldots, x_n, and y1,,yny_1, \ldots, y_n is a random permutations of them. If k\exists k such that yk<yi,1i<ky_k<y_i, \forall 1\le i<k, then we say that yky_k is a record (we always count y1y_1 as a record). What is the expected number of records in y1,,yny_1, \ldots, y_n?

See my neat solution here.