Question 604708:  There are 10 first-tier national rugby union teams. 
(a) How many different two-team pairings are possible among those 10 teams. 
    I guess, the answer to this will be C(10,2) = 45 ways 
I am stuck in the following 
(b) how many different ways are there to select a 1st, 2nd and 3rd ranked teams from these teams 
(c) Suppose 4 teams are going to gather in Sydney, the other 6 teams in Melbourne. How many ways it can be done?
 
Thanks 
 
 Answer by scott8148(6628)      (Show Source): 
You can  put this solution on YOUR website! (b) P(10,3) ___ because order (1st, 2nd or 3rd) is significant
 
 
(c) C(10,4) ___ or C(10,6); the values are the same 
 ___ ALL the teams are selected, so selecting 4 for one venue automatically selects 6 for the other venue 
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