Find all School-related info fast with the new School-Specific MBA Forum

It is currently 26 Oct 2014, 01:50

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Intern
Intern
avatar
Joined: 28 Feb 2012
Posts: 30
Followers: 1

Kudos [?]: 5 [1] , given: 1

You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 [#permalink] New post 02 Jun 2012, 08:22
1
This post received
KUDOS
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

42% (02:13) correct 58% (01:26) wrong based on 57 sessions
You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 centimeters. The number of non-congruent triangles that can be formed by choosing three of the sticks to make the sides is

A. 3
B. 6
C. 7
D. 10
E. 12

OA will be posted after some time.


Please inclease my Kudos if you like the problem...
[Reveal] Spoiler: OA

Last edited by Bunuel on 02 Jun 2012, 11:45, edited 1 time in total.
Edited the question and added the OA
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23422
Followers: 3619

Kudos [?]: 29001 [0], given: 2874

Re: You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 [#permalink] New post 02 Jun 2012, 11:49
Expert's post
sandal85 wrote:
You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 centimeters. The number of non-congruent triangles that can be formed by choosing three of the sticks to make the sides is

A. 3
B. 6
C. 7
D. 10
E. 12

OA will be posted after some time.

Please inclease my Kudos if you like the problem...


The length of any side of a triangle must be larger than the positive difference of the other two sides, but smaller than the sum of the other two sides.

Based on this there can be only 7 triangles formed: (20, 30, 40), (20, 40, 50), (20, 50, 60), (30, 40, 50), (30, 40, 60), (30, 50, 60), (40, 50, 60).

Answer; C.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Director
Director
avatar
Joined: 24 Aug 2009
Posts: 508
Schools: Harvard, Columbia, Stern, Booth, LSB,
Followers: 9

Kudos [?]: 397 [0], given: 241

Re: You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 [#permalink] New post 07 Sep 2012, 11:12
Bunuel wrote:
sandal85 wrote:
You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 centimeters. The number of non-congruent triangles that can be formed by choosing three of the sticks to make the sides is

A. 3
B. 6
C. 7
D. 10
E. 12

OA will be posted after some time.

Please inclease my Kudos if you like the problem...


The length of any side of a triangle must be larger than the positive difference of the other two sides, but smaller than the sum of the other two sides.

Based on this there can be only 7 triangles formed: (20, 30, 40), (20, 40, 50), (20, 50, 60), (30, 40, 50), (30, 40, 60), (30, 50, 60), (40, 50, 60).

Answer; C.


Hi Bunuel,

Is there any other method (combinatorics) to solve this question ?
_________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS.
Kudos always maximizes GMATCLUB worth
-Game Theory

If you have any question regarding my post, kindly pm me or else I won't be able to reply

Manager
Manager
avatar
Joined: 24 Jul 2011
Posts: 77
Location: India
Concentration: Strategy, General Management
GMAT 1: 670 Q49 V33
WE: Asset Management (Manufacturing)
Followers: 2

Kudos [?]: 63 [0], given: 5

Re: You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 [#permalink] New post 09 Sep 2012, 03:32
fameatop wrote:

Hi Bunuel,

Is there any other method (combinatorics) to solve this question ?


Following method may be applied-

As Bunuel has mentioned

"The length of any side of a triangle must be larger than the positive difference of the other two sides, but smaller than the sum of the other two sides."

This a very important characteristic of triangle. [Thanks Bunuel, you are genius !!! ]

Now coming to this particular problem, we have sides mentioned as 10, 20, 30, 40, 50, 60.
Difference between any tow sides is 10, therefore 10 cannot be any side of a triangle.
So, we are left with 20, 30, 40, 50 and 60. ->> 5 sides.

Now, Number of triangles can be formed with 5 sides is ^^5C {^}3 = 10
However, following triangles are not possible-
[ 20, 30, 50 ] -- as 20 + 30 (NOT) > 50

Similarly [20, 30, 60 ] is not possible
Similarly [20, 40, 60] is not possible

[Note: Easiest way to eliminate triangles is to start with least two sides and sum them up. All the sides having equal or higher that value are eliminated. In our case we started with 20 and 30. Hence, 50, and 60 are eliminated.
Repeat the same process with the next number along with the least one. In our case 20 and 40. So, 40 is eliminated. ]

So, finally the number of triangles is 10-3 =7

Hope, this is more logical and quicker method of solving such problem.
_________________

My mantra for cracking GMAT:
Everyone has inborn talent, however those who complement it with hard work we call them 'talented'.


+1 Kudos = Thank You Dear :)
Are you saying thank you?

CEO
CEO
User avatar
Joined: 09 Sep 2013
Posts: 2872
Followers: 208

Kudos [?]: 43 [0], given: 0

Premium Member
Re: You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60 [#permalink] New post 18 May 2014, 08:25
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60   [#permalink] 18 May 2014, 08:25
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic Of 60 children, 30 are happy, 10 are sad, and 20 are neither langtuprovn2007 2 27 Jul 2014, 16:30
1 Experts publish their posts in the topic 740 Q50 V40 6.0 skyadrenaline 5 05 May 2012, 15:47
1 Experts publish their posts in the topic 750 (Q50 V40, AWA 6.0) taken on 7/25/09 lionvish 10 26 Jul 2009, 00:40
2 1001^2)-(999^2)/(101^2)-(99^2) = 10 20 30 50 100 study 6 24 Dec 2008, 02:57
There is a sequence of number only including 30, 40, 50. The getzgetzu 1 05 May 2006, 23:51
Display posts from previous: Sort by

You have 6 sticks of lengths 10, 20, 30, 40, 50, and 60

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.