英语翻译
14.Inthe,amiddleschoolfootballconference,eachteamplayseveryotherteamexactlyonce.Ifatotalof21conferencegameswereplayedduringthe2012season,howmanyteamsweremembersoftheBIGNconference?
Solution
Thisproblemisverysimilartoahandshakeproblem.Weusetheformulatousuallyfindthenumberofgamesplayed(orhandshakes).Nowwehavetousetheformulainreverse.
SowehavetheequationSolving,wefindthatthenumberofteamsintheBIGNconferenceis.
14.IntheBIGN,amiddleschoolfootballconference,eachteamplayseveryotherteamexactlyonce.Ifatotalof21conferencegameswereplayedduringthe2012season,howmanyteamsweremembersoftheBIGNconference?
Solution
Thisproblemisverysimilartoahandshakeproblem.Weusetheformulan(n-1)/2tousuallyfindthenumberofgamesplayed(orhandshakes).Nowwehavetousetheformulainreverse.n(n-1)/2=21