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

It is currently 15 Dec 2018, 19:39

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
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • $450 Tuition Credit & Official CAT Packs FREE

     December 15, 2018

     December 15, 2018

     10:00 PM PST

     11:00 PM PST

    Get the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)
  • FREE Quant Workshop by e-GMAT!

     December 16, 2018

     December 16, 2018

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.

Amy has to visit towns B and C in any order. The roads conne

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

Hide Tags

Intern
Intern
avatar
Joined: 04 Jul 2013
Posts: 6
WE: Consulting (Non-Profit and Government)
Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post Updated on: 05 Jan 2014, 04:52
9
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

57% (01:55) correct 43% (01:54) wrong based on 186 sessions

HideShow timer Statistics

Attachment:
1.gif
1.gif [ 1.68 KiB | Viewed 22722 times ]


Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C (but not more than once through each) and not travelling any road twice on the same trip?

A. 10
B. 8
C. 6
D. 4
E. 2

Source: Other - http://www.majortests.com/gmat/problem_solving_test01

Originally posted by kumar83 on 04 Jan 2014, 22:47.
Last edited by Bunuel on 05 Jan 2014, 04:52, edited 1 time in total.
Renamed the topic and edited the question.
Most Helpful Expert Reply
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8678
Location: Pune, India
Re: Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post 18 Jun 2014, 20:27
6
3
kumar83 wrote:
Attachment:
1.gif


Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C (but not more than once through each) and not travelling any road twice on the same trip?

A. 10
B. 8
C. 6
D. 4
E. 2

Source: Other - http://www.majortests.com/gmat/problem_solving_test01


From A, there are two things Amy can do - go to B or to C. Since the paths are not symmetrical along B and C, you will need to consider them separately.

Case 1: Go to B first
A to B - 1 way
B to C - 2 ways
C to A - 2 ways

Total number of ways in this case = 1*2*2 = 4

Case 2: Go to C first
A to C - 2 ways
C to B - 2 ways
B to A - 1 way

Total number of ways in this case = 2*2*1 = 4

Total number of ways = 4+4 = 8
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

General Discussion
Director
Director
User avatar
B
Joined: 03 Feb 2013
Posts: 850
Location: India
Concentration: Operations, Strategy
GMAT 1: 760 Q49 V44
GPA: 3.88
WE: Engineering (Computer Software)
Reviews Badge
Re: Ques. Amy has to visit towns B and C in any order.  [#permalink]

Show Tags

New post 04 Jan 2014, 23:23
kumar83 wrote:
Source: Other - http://www.majortests.com/gmat/problem_solving_test01

Attachment:
1.gif


Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C (but not more than once through each) and not travelling any road twice on the same trip?
A. 10
B. 8
C. 6
D. 4
E. 2


Clockwise:
Lets assume Weight of A is 1, So the weight of B is 1 as only one route is there to reach.
Weight of C = 1+1 (2 ways to reach C from B) = 2
Weight of A (the last point in the journey ) = 2 + 2 (2 ways to reach A from C) = 4

Similarly for Anti-clokwise :
Lets assume weight of A is 1, so the weight of C = 1+1 (2 ways to reach to C from A) = 2
Weight of B = 2+2 (as there are 2 ways to reach B from C) = 4
Weight to reach A = 4 (as only one way to reach A from C) = 4

hence total is 4+4 = 8 ways (option B))

For any questions on route, this is the best way to solve.
_________________

Thanks,
Kinjal
My Debrief : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267.html#p1449379
My Application Experience : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267-40.html#p1516961
Linkedin : https://www.linkedin.com/in/kinjal-das/

Please click on Kudos, if you think the post is helpful

Director
Director
User avatar
B
Joined: 03 Feb 2013
Posts: 850
Location: India
Concentration: Operations, Strategy
GMAT 1: 760 Q49 V44
GPA: 3.88
WE: Engineering (Computer Software)
Reviews Badge
Re: Ques. Amy has to visit towns B and C in any order.  [#permalink]

Show Tags

New post 04 Jan 2014, 23:32
To make the concept a little more clear, I have just added a example which is attach.

How many ways a person can reach from A to I if only direction allowed to traverse is from left to right?


Weight of A = 1
Weight of B = 1
weight of C = 1
Weight of D = 1
weight of E = 1+1 = 2
weight of F =1
weight of G = 1
weight of H = 1+ 2 + 1 = 4
weight of I = 1 + 4 + 1 = 6

so 6 ways are possible.

The questions can be made a little more complex as there might be a circular path to a node or in one of the path back traversal is allowed (only once for example), then the weights can be calculated again. This method takes care of double counting and with practice, it can be done in secs.
One of my Quant teacher used to say "Clicking the option takes more time than to solve the question". :)
Attachments

File comment: Sample problem in Routes
RouteMapSampleProblems.png
RouteMapSampleProblems.png [ 16.6 KiB | Viewed 21337 times ]


_________________

Thanks,
Kinjal
My Debrief : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267.html#p1449379
My Application Experience : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267-40.html#p1516961
Linkedin : https://www.linkedin.com/in/kinjal-das/

Please click on Kudos, if you think the post is helpful

Manager
Manager
avatar
Joined: 25 Apr 2014
Posts: 112
Re: Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post 18 Jun 2014, 18:54
Hi Bunuel,

Can you shed some light on this concept of weights? Is this type of question frequent in gmat?
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1825
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post 19 Jun 2014, 01:03
3
Refer diagram below:

Possible combinations via route A - B - C - A = 4

a - b1 - c1

a - b1 - c2

a - b2 - c1

a - b2 - c2

Possible combinations via route A - C - B - A = 4

Total = 8

Answer = B
Attachments

1.gif
1.gif [ 2.18 KiB | Viewed 19587 times ]


_________________

Kindly press "+1 Kudos" to appreciate :)

Manager
Manager
avatar
Joined: 25 Apr 2014
Posts: 112
Re: Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post 19 Jun 2014, 05:26
1
Thanks Paresh and Karishma .Kudos to u both :)
Intern
Intern
avatar
Joined: 12 Dec 2013
Posts: 16
Re: Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post 05 Nov 2014, 01:02
Thanks Karishma for a simple explanation. +1 to you!
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9172
Premium Member
Re: Amy has to visit towns B and C in any order. The roads conne  [#permalink]

Show Tags

New post 12 Aug 2018, 16:54
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

GMAT Club Bot
Re: Amy has to visit towns B and C in any order. The roads conne &nbs [#permalink] 12 Aug 2018, 16:54
Display posts from previous: Sort by

Amy has to visit towns B and C in any order. The roads conne

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

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®.