GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 23 Jul 2018, 06:57

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

If one of two parallel lines has 7 points on it and the

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 05 Aug 2008
Posts: 88
Schools: McCombs Class of 2012
If one of two parallel lines has 7 points on it and the  [#permalink]

Show Tags

New post 03 Nov 2008, 10:56
If one of two parallel lines has 7 points on it and the other has 8, how many triangles can be drawn using the points?

a) 168
b) 196
c) 316
d) 364
e) 455

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
1 KUDOS received
VP
VP
avatar
Joined: 17 Jun 2008
Posts: 1476
Re: Number of Triangles  [#permalink]

Show Tags

New post 03 Nov 2008, 11:02
1
D. 364.

Total number of triangles = 7C2*8 + 8C2*7
Manager
Manager
avatar
Joined: 05 Aug 2008
Posts: 88
Schools: McCombs Class of 2012
Re: Number of Triangles  [#permalink]

Show Tags

New post 03 Nov 2008, 11:04
Thanks for the reply scthakur. Can you explain the logic you used to arrive at that? Thank you.
1 KUDOS received
Current Student
avatar
Joined: 28 Dec 2004
Posts: 3287
Location: New York City
Schools: Wharton'11 HBS'12
Re: Number of Triangles  [#permalink]

Show Tags

New post 03 Nov 2008, 11:10
1
basically here is what you are doing

triangle has 3 points..right..

so say on 7 point line you pick any 2 points then on the 8 point line you have to pick 1 point..

7C2*8<--so basically the 2 points are on the 7 point line and the 1 point is on the 8 point line and you have 8 possibilities of picking that 1 point.

next the 2 points of a triangle are on the 8point line so 8C2*7 <-- since now you have 1 pont on the 7point line and as such you have 7 possibilities..
VP
VP
avatar
Joined: 17 Jun 2008
Posts: 1476
Re: Number of Triangles  [#permalink]

Show Tags

New post 03 Nov 2008, 11:13
smarinov wrote:
Thanks for the reply scthakur. Can you explain the logic you used to arrive at that? Thank you.


Good explanation from freshinha is there now.
Manager
Manager
avatar
Joined: 05 Aug 2008
Posts: 88
Schools: McCombs Class of 2012
Re: Number of Triangles  [#permalink]

Show Tags

New post 03 Nov 2008, 11:15
Thank you both. I get it now.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Re: Number of Triangles &nbs [#permalink] 03 Nov 2008, 11:15
Display posts from previous: Sort by

If one of two parallel lines has 7 points on it and the

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderator: chetan2u

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.