Don't have the answer for this question.
A baseball league has 13 teams, and each team plays each other twice; once at home, and once away. How many games are scheduled?
logical approach: any team plays with rest 12 teams. so each plays 12 games but in that 12 games 1 game of each of 12 teams game is included. so the next team (2nd team) plays 11 games. The next team (3rd team) plays 10 games and so on. Add up all.
= 2 (12+11+10+ ..............+ 1)
= 2 x 78
= 156 games.