Source: GMAT Paper Tests
In the diagram above, points A, B, C, D, and E represent the five teams in a certain league in which each team must play each of the other teams exactly once. The segments connecting pairs of points indicate that the two corresponding teams have already played their game. The arrows on the segments point to the teams that lost; the lack of an arrow on a segment indicates that the game ended in a tie. After all games have been played, which of the following could NOT be the percent of games played that ended in a tie?
A. 10%
B. 20%
C. 30%
D. 40%
E. 50%
The OA is A
In the diagram above, points A, B, C, D, and E represent the
This topic has expert replies
-
- Moderator
- Posts: 2207
- Joined: Sun Oct 15, 2017 1:50 pm
- Followed by:6 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
points A, B, C, D, and E represent the five teams in a certain league in which each team must play each of the other teams exactly once.BTGmoderatorLU wrote:Source: GMAT Paper Tests
In the diagram above, points A, B, C, D, and E represent the five teams in a certain league in which each team must play each of the other teams exactly once. The segments connecting pairs of points indicate that the two corresponding teams have already played their game. The arrows on the segments point to the teams that lost; the lack of an arrow on a segment indicates that the game ended in a tie. After all games have been played, which of the following could NOT be the percent of games played that ended in a tie?
A. 10%
B. 20%
C. 30%
D. 40%
E. 50%
The OA is A
Let's first determine the total number of games that will be played.
There are 5 teams, so each team will play 4 games (since a team can't play itself)
So, the total number of games = (5)(4) = 20
From here we need to recognize that every game has been counted TWICE.
For example, if Team A and Team B play a game, then Team A counts it as a game, AND Team B counts it as a game. Of course only one game occurred.
To account for the duplication, we'll divide 20 by 2 to get 10
So, there will be a total of 10 games.
After all games have been played, which of the following could NOT be the percent of games played that ended in a tie?
Scan the answer choices.
Answer choice A says 10%
In order to have 10% of the games ending in a tie, we need 1 of the 10 games to end in a tie.
However, from the diagram, we can see that 2 ties have already occurred.
So, answer choice A is cannot happen.
Answer: A
Cheers,
Brent