It is currently 17 Oct 2017, 05:06

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# There are 8 teams in a certain league and each team plays each of the

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Manager
Joined: 10 Nov 2010
Posts: 247

Kudos [?]: 401 [0], given: 22

Location: India
Concentration: Strategy, Operations
GMAT 1: 520 Q42 V19
GMAT 2: 540 Q44 V21
WE: Information Technology (Computer Software)
There are 8 teams in a certain league and each team plays each of the [#permalink]

### Show Tags

20 Feb 2011, 09:13
1
This post was
BOOKMARKED
00:00

Difficulty:

15% (low)

Question Stats:

73% (00:29) correct 27% (00:34) wrong based on 66 sessions

### HideShow timer Statistics

There are 8 teams in a certain league and each team plays each of the other teams exactly once. If each game is played by 2 teams, what is the total number of games played?

A. 15
B. 16
C. 28
D. 56
E. 64

OPEN DISCUSSION OF THIS QUESTION IS HERE: there-are-8-teams-in-a-certain-league-and-each-team-plays-134582.html
[Reveal] Spoiler: OA

Attachments

no-of-games-played.JPG [ 23.04 KiB | Viewed 2173 times ]

_________________

The proof of understanding is the ability to explain it.

Kudos [?]: 401 [0], given: 22

Math Forum Moderator
Joined: 20 Dec 2010
Posts: 1964

Kudos [?]: 2049 [0], given: 376

Re: There are 8 teams in a certain league and each team plays each of the [#permalink]

### Show Tags

20 Feb 2011, 09:17
Number of ways 2 teams can be selected out of 8 teams:

$$C^8_2=\frac{8*7}{2}=28$$

Ans:"C"
_________________

Kudos [?]: 2049 [0], given: 376

Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7670

Kudos [?]: 17327 [0], given: 232

Location: Pune, India
Re: There are 8 teams in a certain league and each team plays each of the [#permalink]

### Show Tags

20 Feb 2011, 20:20
GMATD11 wrote:
sol

8th team will play 7 games with 7 teams, so total number of games played by 8th team is 7
similarly 7----------------6------------6------------------------------------------ 7----------- 6
--------6----------------5------------5------------------------------------------ 8----------- 5
nd so on

total games played= 7+6+5+4+3+2+1=28

any other optimal sol.

Your reasoning is perfect.... Just that to perform 7+6+5+4+3+2+1, use the formula n(n+1)/2 where n = 7.
7*8/2 = 28
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Kudos [?]: 17327 [0], given: 232

Senior Manager
Joined: 08 Nov 2010
Posts: 394

Kudos [?]: 128 [0], given: 161

WE 1: Business Development
Re: There are 8 teams in a certain league and each team plays each of the [#permalink]

### Show Tags

21 Feb 2011, 11:41
in what cases u will use the formula n(n+1)/2?
_________________

Kudos [?]: 128 [0], given: 161

Math Forum Moderator
Joined: 20 Dec 2010
Posts: 1964

Kudos [?]: 2049 [1], given: 376

Re: There are 8 teams in a certain league and each team plays each of the [#permalink]

### Show Tags

21 Feb 2011, 11:48
1
KUDOS
144144 wrote:
in what cases u will use the formula n(n+1)/2?

Just to add first n natural numbers; that's all

1+2+3+4+5
Here n=5; Sum = n(n+1)/2 = 5*6/2=15

1+2+3+4+5+6+7+8+9
Here n=5; Sum = n(n+1)/2 = 9*10/2=45

In the above example;
7+6+5+4+3+2+1
Sum of natural numbers from 1 to 7 = 7*8/2 = 56/2 = 28.

It easy this way rather than adding every number.
_________________

Kudos [?]: 2049 [1], given: 376

Math Expert
Joined: 02 Sep 2009
Posts: 41871

Kudos [?]: 128527 [0], given: 12180

Re: There are 8 teams in a certain league and each team plays each of the [#permalink]

### Show Tags

17 Aug 2015, 10:28
GMATD11 wrote:
There are 8 teams in a certain league and each team plays each of the other teams exactly once. If each game is played by 2 teams, what is the total number of games played?

A. 15
B. 16
C. 28
D. 56
E. 64

The total # of games played would be equal to the # of different pairs possible from 8 teams, which is $$C^2_{8}=28$$.

OPEN DISCUSSION OF THIS QUESTION IS HERE: there-are-8-teams-in-a-certain-league-and-each-team-plays-134582.html
_________________

Kudos [?]: 128527 [0], given: 12180

Re: There are 8 teams in a certain league and each team plays each of the   [#permalink] 17 Aug 2015, 10:28
Display posts from previous: Sort by

# There are 8 teams in a certain league and each team plays each of the

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.