Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Combinatorics: Soccer Tournament Outcomes; r-permutations and r-combinations of sets

  1. Sep 19, 2011 #1
    1. The problem statement, all variables and given/known data
    In a soccer tournament of 15 teams, the top three teams are awarded gold, silver, and bronze cups, and the last three teams are dropped to a lower league. We regard two outcomes of the tournament as the same if the teams that receive the gold, silver, and bronze cups, respectively, are identical and the teams which drop to a lower league are also identical. How many different possible outcomes are there for the tournament?

    2. Relevant equations
    n-combinations on k objects: n choose k = n!/[k!(n-k)!]
    n-permutations on r objects: n!/(n-r)!

    3. The attempt at a solution
    So there will be 3 teams rewarded, and 3 teams bumped down a league.

    The middle 6 teams placements are not identical, so they are ordered, so use permutations to figure out how many ways to order 6 teams in 6 places: [6]6 = 6!/(6-6)! = 6! ways to order 6 teams in 6 places.

    I'm having trouble figuring out the number of possibilities with the first and last 3 teams.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?