Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack
GMAT Club

It is currently 26 Mar 2017, 23:44

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

Events & Promotions in June
Open Detailed Calendar

Stations X and Y are connected by two separate, straight,

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

Hide Tags

Expert Post
1 KUDOS received
Math Expert
User avatar
P
Joined: 02 Sep 2009
Posts: 37593
Followers: 7402

Kudos [?]: 99621 [1] , given: 11024

Re: DS -Relative Speed - Set 14 [#permalink]

Show Tags

New post 26 Sep 2010, 04:24
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
Stations X and Y are connected by two separate, straight, parallel rail lines that are 250 miles long. Train P and train Q simultaneously left Station X and Station Y, respectively, and each train traveled to the other’s point of departure. The two trains passed each other after traveling for 2 hours. When the two trains passed, which train was nearer to its destination?
(1) At the time when the two trains passed, train P had averaged a speed of 70 miles per hour.
(2) Train Q averaged a speed of 55 miles per hour for the entire trip.

(1) As P averaged 70 miles per hour at the time when the two trains passed, hence when they passed each other P traveled 2*70=140 miles, so for P it was 110 miles left to cover and for Q 140. P was closer to its destination. Sufficient.

(2) Knowing average speed for entire trip won't help us to determine the distance either of train coverd at the time they passed each other (as the average speed at the time the met could have been different). Not sufficient.

Answer: A.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Expert Post
Math Expert
User avatar
P
Joined: 02 Sep 2009
Posts: 37593
Followers: 7402

Kudos [?]: 99621 [0], given: 11024

Re: DS -Relative Speed - Set 14 [#permalink]

Show Tags

New post 17 Oct 2010, 05:48
Current Student
User avatar
Joined: 06 Sep 2013
Posts: 2030
Concentration: Finance
GMAT 1: 770 Q0 V
Followers: 65

Kudos [?]: 623 [0], given: 355

GMAT ToolKit User
Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 31 Dec 2013, 08:05
tenaman10 wrote:
Stations X and Y are connected by two separate, straight, parallel rail lines that are 250 miles long. Train P and train Q simultaneously left Station X and Station Y, respectively, and each train traveled to the other’s point of departure. The two trains passed each other after traveling for 2 hours. When the two trains passed, which train was nearer to its destination?

(1) At the time when the two trains passed, train P had averaged a speed of 70 miles per hour.
(2) Train Q averaged a speed of 55 miles per hour for the entire trip.


Clear A, from question stem, one gets the following

(P+Q)(2) = 250

(P+Q) = 125

Statement 1

P= 70 --> Q= 55

Suff

Statement 2

Not suff

Hence A is the correct answer

Hope it helps!
Cheers!

J :)
Manager
Manager
avatar
Joined: 25 Oct 2013
Posts: 172
Followers: 1

Kudos [?]: 57 [0], given: 56

Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 11 Jan 2014, 07:38
Yes it is A. Stmt 2 is tricky. We should not assume speed of Q is constant. It got me.
_________________

Click on Kudos if you liked the post!

Practice makes Perfect.

Senior Manager
Senior Manager
avatar
Joined: 28 Apr 2014
Posts: 289
Followers: 1

Kudos [?]: 35 [0], given: 46

GMAT ToolKit User
Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 01 May 2014, 06:48
What is the right answer ? To me both alone are sufficient.
Expert Post
Math Expert
User avatar
P
Joined: 02 Sep 2009
Posts: 37593
Followers: 7402

Kudos [?]: 99621 [0], given: 11024

Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 01 May 2014, 07:05
Manager
Manager
avatar
Joined: 20 Oct 2013
Posts: 66
Followers: 0

Kudos [?]: 2 [0], given: 27

Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 05 May 2014, 23:28
HI bunnel

Please explain once the concept of average speed... as in when we need the average speed of entire trip and when we need average speed at the time of meeting
_________________

Hope to clear it this time!!
GMAT 1: 540
Preparing again :(

Expert Post
Math Expert
User avatar
P
Joined: 02 Sep 2009
Posts: 37593
Followers: 7402

Kudos [?]: 99621 [0], given: 11024

Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 06 May 2014, 03:21
nandinigaur wrote:
HI bunnel

Please explain once the concept of average speed... as in when we need the average speed of entire trip and when we need average speed at the time of meeting


Not sure I follow... Generally (average speed) = (total distance)/(total time) ...

Theory on Distance/Rate Problems: distance-speed-time-word-problems-made-easy-87481.html

All DS Distance/Rate Problems to practice: search.php?search_id=tag&tag_id=44
All PS Distance/Rate Problems to practice: search.php?search_id=tag&tag_id=64


Hope this helps.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Manager
Manager
User avatar
Joined: 03 Jan 2015
Posts: 68
Concentration: Strategy, Marketing
WE: Research (Pharmaceuticals and Biotech)
Followers: 2

Kudos [?]: 32 [0], given: 224

GMAT ToolKit User
Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 20 Jan 2015, 10:32
Stations X and Y are connected by two separate, straight, parallel rail lines that are 250 miles long. Train P and train Q simultaneously left Station X and Station Y, respectively, and each train traveled to the other’s point of departure. The two trains passed each other after traveling for 2 hours. When the two trains passed, which train was nearer to its destination?

(1) At the time when the two trains passed, train P had averaged a speed of 70 miles per hour.
(2) Train Q averaged a speed of 55 miles per hour for the entire trip


SOLUTION:

D = 250 miles
P and Q travel 2 hrs each before they meet

From (1): P speed = 70 mph i.e. in 2 hrs it covers 140 miles
Therefore, Q must have traveled = 110 miles ---- SUFFICIENT

From (2): Q speed for ENTIRE trip = 55 mph ---- Clearly INSUFFICIENT

ANSWER: A
Intern
Intern
avatar
Joined: 07 Apr 2016
Posts: 2
Followers: 0

Kudos [?]: 0 [0], given: 15

Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 09 Apr 2016, 14:52
i think it should be E.

1) it says "At the time the 2 trains passed" train P averaged 70 mph. Which means that the speed could've been more or less before. what if it was going at a speed of 30 mph and all along and then was at 70 around when it crossed train Q.

2) Train Q averaged 55 mph for the entire trip.

Here we're comparing apples to oranges as one states the speed when the trains crossed and one states the average speed. If both had average speeds in the question, it would be a fair comparison.
Expert Post
Math Expert
User avatar
P
Joined: 02 Sep 2009
Posts: 37593
Followers: 7402

Kudos [?]: 99621 [0], given: 11024

Re: Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 09 Apr 2016, 15:09
achalbhatt wrote:
i think it should be E.

1) it says "At the time the 2 trains passed" train P averaged 70 mph. Which means that the speed could've been more or less before. what if it was going at a speed of 30 mph and all along and then was at 70 around when it crossed train Q.

2) Train Q averaged 55 mph for the entire trip.

Here we're comparing apples to oranges as one states the speed when the trains crossed and one states the average speed. If both had average speeds in the question, it would be a fair comparison.


The correct answer is given under the spoiler in the original post and it's A. Solution is here: stations-x-and-y-are-connected-by-two-separate-straight-77177-20.html#p788611

Hope it helps.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

Director
Director
User avatar
Joined: 04 Jun 2016
Posts: 658
GMAT 1: 750 Q49 V43
Followers: 54

Kudos [?]: 235 [0], given: 36

Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 01 Aug 2016, 03:56
Stations X and Y are connected by two separate, straight, parallel rail lines that are 250 miles long. Train P and train Q simultaneously left Station X and Station Y, respectively, and each train traveled to the other’s point of departure. The two trains passed each other after traveling for 2 hours. When the two trains passed, which train was nearer to its destination?

(1) At the time when the two trains passed, train P had averaged a speed of 70 miles per hour.
Train P has been running for 2 hours with an average speed of 70 miles per hour so it has covered 140 km .
The total distance is 250; so P was 250-140= 90 miles away from its destination .
We can use logic to see that since the train are crossing each other then train Q must also travelled 90 kilometres and thus it was 250-90 = 160 km away from its destination
Train P was closer
SUFFICIENT

(2) Train Q averaged a speed of 55 miles per hour for the entire trip.
Well the speed for first hour can vary from the second's hour's speed and so on.
We don know at what speed train Q travelled for the first 2 hours so we cannot figure out its distance.
INSUFFICIENT

ANSWER IS A
_________________

Posting an answer without an explanation is "GOD COMPLEX". The world doesn't need any more gods. Please explain you answers properly.
FINAL GOODBYE :- 17th SEPTEMBER 2016. .. 16 March 2017 - I am back but for all purposes please consider me semi-retired.

Intern
Intern
avatar
Joined: 06 Dec 2016
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 2

Stations X and Y are connected by two separate, straight, [#permalink]

Show Tags

New post 08 Dec 2016, 00:09
I don't know, but this one seems actually quite easy to me. Statement 1 says that at the time when the two trains passed, train P had average speed of 70 mph, that is after traveling 2 hours, which makes it 140. The rail lines are parallel and 250 long, meaning train P is 110 miles from its destination (250-140), while train Q was 140 miles from its destination. Hence, statement 1 is sufficient. Hope it is clear.
Stations X and Y are connected by two separate, straight,   [#permalink] 08 Dec 2016, 00:09

Go to page   Previous    1   2   [ 33 posts ] 

    Similar topics Author Replies Last post
Similar
Topics:
4 Experts publish their posts in the topic If x and y are two different integers, is |x|=|y|? chetan2u 4 17 Feb 2017, 20:19
4 Experts publish their posts in the topic A train traveled from station X to station Y at a constant speed of 88 Bunuel 4 23 Jun 2016, 03:01
Experts publish their posts in the topic Stations M and N are connected by two separate, straight and parallel geometric 1 28 Apr 2016, 13:59
36 Experts publish their posts in the topic While on a straight road, Car X and Car Y are traveling at vix 13 17 Mar 2012, 18:44
7 Experts publish their posts in the topic Stations X and Y are connected by two separate, straight, udaymathapati 8 30 Aug 2010, 10:23
Display posts from previous: Sort by

Stations X and Y are connected by two separate, straight,

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


GMAT Club MBA Forum Home| About| 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®.