Exercise 1: Awarding Gold, Silver, and Bronze Among 8 Racers — Possible Solution ==================================================================== IDENTIFYING WHICH FORMULA APPLIES ------------------------------ This is a permutation problem, not a combination problem - per this chapter's own guiding question, "does the arrangement or order of the selected items actually matter for this problem?" Here it clearly does: winning gold versus winning bronze are genuinely different outcomes, even for the exact same three racers. Choosing which 3 racers place, AND which specific medal each of them gets, means order matters. SETTING UP THE CALCULATION ------------------------------ This is P(n, r) with n = 8 (total racers) and r = 3 (medal positions being filled): P(8, 3) = 8! / (8 - 3)! = 8! / 5! COMPUTING THE RESULT ------------------------------ Rather than computing the full factorials, the 5! in the denominator cancels with the bottom of 8!, leaving only the top 3 factors: 8! / 5! = 8 x 7 x 6 x 5! / 5! = 8 x 7 x 6 = 336 So there are 336 different ways to award gold, silver, and bronze among 8 racers. WHY THIS INTUITIVELY MAKES SENSE AS A CHAIN OF CHOICES ------------------------------ This also follows directly from this chapter's own multiplication principle: there are 8 choices for who gets gold, then 7 remaining racers to choose from for silver, then 6 remaining for bronze - 8 x 7 x 6 = 336, exactly matching the formula's own result. The factorial formula and this direct "chain of diminishing choices" reasoning always agree, since that's precisely what n!/(n-r)! is computing. WHY THIS WORKS AS AN ANSWER ------------------------------ It explicitly justifies why this is a permutation rather than a combination using this chapter's own guiding question, sets up and computes the formula correctly, and cross-checks the result using an independent multiplication-principle argument that arrives at the same number.