Let there be a cube with sides denoted each. The cube is tossed times. For what is the probability that exactly first tosses give different number (i.e, the -st toss give a number that was already gotten.) I really need to know why I got a slightly different answer from the official one.My attempt: Let us build a uniform sample space. . , . We seek for the event This is the problematic part: . (Then I and the answer use the formula for probability of an even it a uniform sample space.)The point is, the answer says: I don't understand why; First I pick numbers, count all their permutations, then pick one of them for the -th toss, and then I have tosses left, each of which has possibilities.