A set of football matches is to
be organized in a "round-robin"
fashion, i.e., every participating
team plays a match against
every other team once and only
once.
If 21 matches are totally played,
how many teams participated?

• 7
  the sum of number of matches played= n(n+1)/2=21; n=6 and hence number of teams=6+1(the team itself)=7
  
• 13 years agoHelpfull: Yes(7) No(3)
• In Round Robin Matches Played Are NC2 Where "N" Is No Of Teams...Given NC2=21=>N=7
• 13 years agoHelpfull: Yes(3) No(1)
• Ans:7
  Let us assume there are x teams then
  Team1 will play – (x-1) matches
  Team 2 will play- (x-2)
  Team 3 will play –(x-3)
  …………………………
  …………………………
  Team x-2 will play -2 matches
  Team x-1 will play –1match
  Team x will play – 0 matches
  Therefore,Total matches=1+2+3+4+……………+(x-1)
  =>x(x-1)/2=21 (since total matches=21)
  =>x= 7 (or) x=-6
  No of teams cannot be –ve , X=7
• 7 years agoHelpfull: Yes(1) No(0)
• 7 teams are there
• 13 years agoHelpfull: Yes(0) No(4)