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guest
 
 

if each of the 6 teams in the league played each

by guest Tue Sep 04, 2007 5:40 pm

Hi, can someone show me how to approach this problem-

Incomplete table:
Team A - won 4 games
Team B - won 7 games
Team C - won 9 games
Team D - won 2 games
Team E - won 2 games
Team X - ?

if each of the 6 teams in the league played each of the other teams exactly twice and there were no ties, how many games did team C win? (only 2 teams play in a game.)
abramson
 
 

by abramson Tue Sep 04, 2007 6:11 pm

Count down the list:

Team A played 10 games in total (2 games with each of the other 5 teams)
Team B played 8 games. (Don't count the games it played with A again)
Team C played 6.

In this way, you arrive at 30 games played total.
Count the number of wins (the data supplied adds up to 24 games won).
Since no games were a draw, team X must have won the remaining games. Which comes to (30 - 24) = 6.

Hope this helps!
dbernst
ManhattanGMAT Staff
 
Posts: 300
Joined: Mon May 09, 2005 9:03 am
 

by dbernst Thu Sep 06, 2007 2:03 pm

Guest, another approach to calculate the number of games played is to approach this as a combinatorics problem. There are six teams, and we are solving for the number of combinations that include two of the teams. Thus, for each team to play each other once, there are 6!/2!4! or 15 combinations (i.e. games). Simply double this number to calculate the number of games for each team to play each of the other teams twice.

Then, simply subtract 24 (the total number of games played by teams other than X) from 30 (the total number of games played) and 6 is the correct result.

-dan

Hi, can someone show me how to approach this problem-

Incomplete table:
Team A - won 4 games
Team B - won 7 games
Team C - won 9 games
Team D - won 2 games
Team E - won 2 games
Team X - ?

if each of the 6 teams in the league played each of the other teams exactly twice and there were no ties, how many games did team C win? (only 2 teams play in a game.)