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

It is currently 17 Sep 2014, 08:18

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

Train A leaves New York for Boston at 3 PM and travels at

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
3 KUDOS received
Manager
Manager
User avatar
Joined: 19 Aug 2006
Posts: 222
Followers: 1

Kudos [?]: 9 [3] , given: 0

GMAT Tests User
Train A leaves New York for Boston at 3 PM and travels at [#permalink] New post 30 May 2007, 20:16
3
This post received
KUDOS
6
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

23% (03:29) correct 77% (02:32) wrong based on 145 sessions
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?

(1) Train B arrived in New York before Train A arrived in Boston.
(2) The distance between New York and Boston is greater than 140 miles.

OPEN DISCUSSION OF THIS QUESTION IS HERE: train-a-leaves-new-york-for-boston-at-3-pm-and-travels-at-97694.html
[Reveal] Spoiler: OA

Last edited by Bunuel on 02 Jun 2014, 01:41, edited 2 times in total.
OA added.
Kaplan Promo CodeKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Manager
Manager
User avatar
Joined: 19 Aug 2006
Posts: 222
Followers: 1

Kudos [?]: 9 [0], given: 0

GMAT Tests User
 [#permalink] New post 30 May 2007, 21:08
No!! think more...

This is tough question.
Senior Manager
Senior Manager
User avatar
Joined: 04 Mar 2007
Posts: 447
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
 [#permalink] New post 30 May 2007, 22:57
C :)
Manager
Manager
avatar
Joined: 25 May 2007
Posts: 232
Schools: Cornell
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
 [#permalink] New post 30 May 2007, 23:36
vidyasagar wrote:
E.


E.

Neither (1) and (2) provides informative figure for calculation...
Manager
Manager
User avatar
Joined: 19 Aug 2006
Posts: 222
Followers: 1

Kudos [?]: 9 [0], given: 0

GMAT Tests User
 [#permalink] New post 31 May 2007, 01:05
Come on guyzz!!

Think Hard!! This is really nasty question.
Manager
Manager
avatar
Joined: 25 May 2007
Posts: 232
Schools: Cornell
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
 [#permalink] New post 31 May 2007, 01:40
johnycute wrote:
Come on guyzz!!

Think Hard!! This is really nasty question.


Hell... It first appeared to me an easy question. Seems not. How would we realize a TRICKY question?

:roll:
Senior Manager
Senior Manager
User avatar
Joined: 04 Mar 2007
Posts: 447
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
Re: DS- Time/Distance [#permalink] New post 31 May 2007, 02:15
johnycute wrote:
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?
(1) Train B arrived in New York before Train A arrived in Boston.

(2) The distance between New York and Boston is greater than 140 miles.


Train B has already travelled for 10 min
Train A - for 1 hour.
The total combined time for both will be 2 hrs. Hence 50 min of combined time left for the trains to reach each its own destination.
T2(A) + T2(B) = 50/60
Distance1(A)=Distance2(B)=1hour*100mph=100m - distance covered by A and which must be yet covered by B.
We need to find out time which will be consumed by B to travel 100 m. We need to know the speed of B.
Let's take (1) - Train B arrived in New York before Train A arrived in Boston.
It gives us nothing - INSUFF
Let's take (2) - The distance between New York and Boston is greater than 140 miles.
Distance1(B)>140-100 i.e. B has already travelled for more than 40 miles
It took him 10/60 hours as he left at 3.50 PM and met A at 4.00PM
hence Speed(B) > 240 mph
T2(B) < 100/240 i.e. time left for B to arrive to New York is less than 25 minutes.
It can be 24, 23, 22 minutes and so on....
Let's take now (1) and (2) together.
As T(A) + T(B) = 50/60
and T(B) < 25/60
then T(A) is more or equal to 25 and less than 50
We know that Train B arrived in New York before Train A arrived in Boston. I.e. T(B) is less than T(A).

I don't know
I am getting E here.
Could you please point out fault in my logic?
2 KUDOS received
Manager
Manager
User avatar
Joined: 19 Aug 2006
Posts: 222
Followers: 1

Kudos [?]: 9 [2] , given: 0

GMAT Tests User
Re: DS- Time/Distance [#permalink] New post 31 May 2007, 21:59
2
This post received
KUDOS
1
This post was
BOOKMARKED
johnycute wrote:
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?
(1) Train B arrived in New York before Train A arrived in Boston.

(2) The distance between New York and Boston is greater than 140 miles.


The question is very tough and it took me lot of time to solve it....

Lets first rephrase the question.

Consider for train B:
Rate=r; Time=t; Distance=d
ForTrain A:
Rate=100mph;Time=2-t;Dist=d

Now from this information we know 2 equations.
d=100(2-t) ----------------(A)

d=rt-------------------------(B)

We also know that when the trains pass each other (going in opposite directions), Train A has been traveling for 1 hour and Train B has been traveling for 10 minutes or 1/6 of an hour.

This means that Train A has traveled 100 miles and Train B has traveled r/6 miles.
Thus, the total distance from New York to Boston can be expressed using the equation

d=100+r/6------------------(C)

If we compare A and B;

t=200/100+r----------------(D)

Now compare equation B and C and put the value of "t" from equation D.

r(200/100+r) = 100 + r/6

(r-300)(r-200)=0

Thus, the rate, r, of Train B is either 300 mph or 200 mph.

If Train B has a rate of 300 mph. It travels 50 miles in 1/6 hour, at which point it meets Train A which has already traveled 100 miles. Therefore, the total distance from Boston to New York must be 150 miles. Thus, Train B's total traveling time was 1/2 hour, and Train A's total traveling time was 1 1/2 hours. Train B arrived in New York at 4:20 PM and Train A arrived in Boston at 4:30 PM.

If Train B has a rate of 200 mph. It travels 33 1/3 miles in 1/6 hour, at which point it meets Train A which has already traveled 100 miles. Therefore, the total distance from Boston to New York must be 133 1/3 miles. Thus Train B's total traveling time was 2/3 hour, and Train A's total traveling time was 1 1/3 hours. Train B arrived in New York at 4:30 PM and Train A arrived in Boston at 4:20 PM.

Statement (1) tells us that Train B arrived in New York before Train A arrived in Boston. From this, we know that Scenario 1 must have occurred and Train B arrived in New York at 4:20 PM. We have sufficient information to answer the question. :)

Statement (2) tells us that the distance between New York and Boston is greater than 140 miles. This means that Scenario 2 is not possible so Scenario 1 must have occurred: Train B arrived in New York at 4:20 PM. Again, we have sufficient information :)
to answer the question.

The correct answer is (D): Each statement ALONE is sufficient :-D :-D
Senior Manager
Senior Manager
User avatar
Joined: 04 Mar 2007
Posts: 447
Followers: 1

Kudos [?]: 12 [0], given: 0

GMAT Tests User
 [#permalink] New post 31 May 2007, 22:43
Johny, you are really cute :)
Thanks for your explanation. It is really helpfull.
Director
Director
User avatar
Joined: 14 Jan 2007
Posts: 782
Followers: 2

Kudos [?]: 52 [0], given: 0

GMAT Tests User
 [#permalink] New post 01 Jun 2007, 01:50
good question. But solvable in 3 minutes.
Manager
Manager
User avatar
Joined: 22 Jul 2009
Posts: 192
Followers: 4

Kudos [?]: 189 [0], given: 18

GMAT Tests User
Re: DS- Time/Distance [#permalink] New post 22 Sep 2009, 15:48
This is the most difficult DS RTD question I remember seeing.

It requires solving, and calculations are long.
_________________

Please kudos if my post helps.

Expert Post
7 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 29665
Followers: 3494

Kudos [?]: 26267 [7] , given: 2708

Re: DS- Time/Distance [#permalink] New post 04 Oct 2009, 16:32
7
This post received
KUDOS
Expert's post
Make it simple:

Let:
d be the distance between cities;
x be the rate of Train B.

"An hour later (so at 4:00PM), Train A passes Train B" --> before they pass each other A traveled 1 hour (4PM-3PM) and B traveled 1/6 hours (4PM-3:50PM).

"Combined travel time of the two trains is 2 hours" --> d/100(time to cover all distance for train A)+d/x(time to cover all distance for train B)=2 --> \frac{d}{100}+\frac{d}{x}=2;

As before they pass A traveled 100 miles (1 hour at 100 miles per hour), then distance to cover for B after they pass is this 100 miles and as B traveled x*1/6 miles before they pass (1/6 hour at x miles per hour), then distance to cover for A after they pass is this x*1/6 miles --> 100+\frac{x}{6}=d;

So, we have:
\frac{d}{100}+\frac{d}{x}=2 and 100+\frac{x}{6}=d.

Solving for d and x
d=150 and x=300;
OR:
d=\frac{800}{6}\approx{133.3} and x=200.

(1) Says that train B arrived before A.
If x=200 A arrives at 4:20, B at 4:30, not good;
If x=300 A arrives at 4:30, B at 4:20, OK.
Sufficient

(2) Says that d>140 --> d=150 --> x=300, arrival time for B 4:20. Sufficient

Answer D.

Hope it's clear.
_________________

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

Manager
Manager
avatar
Joined: 05 Jul 2009
Posts: 182
Followers: 1

Kudos [?]: 14 [0], given: 5

Re: DS- Time/Distance [#permalink] New post 05 Oct 2009, 01:04
Nicely explained Bunuel!

I think it is one of the most hardest DS questions I have ever faced!!! Even after the explanation it took me a lot of time to solve by myself.
SVP
SVP
User avatar
Joined: 09 Sep 2013
Posts: 2414
Followers: 196

Kudos [?]: 38 [0], given: 0

Premium Member
Re: Train A leaves New York for Boston at 3 PM and travels at [#permalink] New post 07 Jan 2014, 19:52
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

Intern
Intern
avatar
Joined: 14 Nov 2012
Posts: 4
Followers: 0

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

Re: Train A leaves New York for Boston at 3 PM and travels at [#permalink] New post 08 Jan 2014, 06:24
I thought answer was C

these questions can really make you feel stupid...
Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 29665
Followers: 3494

Kudos [?]: 26267 [1] , given: 2708

Re: Train A leaves New York for Boston at 3 PM and travels at [#permalink] New post 08 Jan 2014, 06:28
1
This post received
KUDOS
Expert's post
masokaz wrote:
I thought answer was C

these questions can really make you feel stupid...


This is a very tough problem. So, don't be discouraged if you solved it wrong.

You can check more solutions of the problem here: train-a-leaves-new-york-for-boston-at-3-pm-and-travels-at-97694.html

Hope this helps.
_________________

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

Manager
Manager
avatar
Joined: 04 Jan 2014
Posts: 125
Followers: 1

Kudos [?]: 5 [0], given: 24

Re: DS- Time/Distance [#permalink] New post 27 May 2014, 23:12
Bunuel wrote:
Make it simple:

Let:
d be the distance between cities;
x be the rate of Train B.

"An hour later (so at 4:00PM), Train A passes Train B" --> before they pass each other A traveled 1 hour (4PM-3PM) and B traveled 1/6 hours (4PM-3:50PM).

"Combined travel time of the two trains is 2 hours" --> d/100(time to cover all distance for train A)+d/x(time to cover all distance for train B)=2 --> \frac{d}{100}+\frac{d}{x}=2;

As before they pass A traveled 100 miles (1 hour at 100 miles per hour), then distance to cover for B after they pass is this 100 miles and as B traveled x*1/6 miles before they pass (1/6 hour at x miles per hour), then distance to cover for A after they pass is this x*1/6 miles --> 100+\frac{x}{6}=d;

So, we have:
\frac{d}{100}+\frac{d}{x}=2 and 100+\frac{x}{6}=d.



Hi Bunnel

I don't understand why do we have to add 100+\frac{x}{6}=d ?

Thanks
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 29665
Followers: 3494

Kudos [?]: 26267 [0], given: 2708

Re: DS- Time/Distance [#permalink] New post 02 Jun 2014, 01:41
Expert's post
pretzel wrote:
Bunuel wrote:
Make it simple:

Let:
d be the distance between cities;
x be the rate of Train B.

"An hour later (so at 4:00PM), Train A passes Train B" --> before they pass each other A traveled 1 hour (4PM-3PM) and B traveled 1/6 hours (4PM-3:50PM).

"Combined travel time of the two trains is 2 hours" --> d/100(time to cover all distance for train A)+d/x(time to cover all distance for train B)=2 --> \frac{d}{100}+\frac{d}{x}=2;

As before they pass A traveled 100 miles (1 hour at 100 miles per hour), then distance to cover for B after they pass is this 100 miles and as B traveled x*1/6 miles before they pass (1/6 hour at x miles per hour), then distance to cover for A after they pass is this x*1/6 miles --> 100+\frac{x}{6}=d;

So, we have:
\frac{d}{100}+\frac{d}{x}=2 and 100+\frac{x}{6}=d.



Hi Bunnel

I don't understand why do we have to add 100+\frac{x}{6}=d ?

Thanks


When the trains pass each other A covered 100 miles and B covered x/6 miles. Together they covered the whole distance of d miles, no?

{NY}----(100 miles)----{meeting point}--(x/6 miles)--{Boston}

OPEN DISCUSSION OF THIS QUESTION IS HERE: train-a-leaves-new-york-for-boston-at-3-pm-and-travels-at-97694.html
_________________

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

Re: DS- Time/Distance   [#permalink] 02 Jun 2014, 01:41
    Similar topics Author Replies Last post
Similar
Topics:
4 Experts publish their posts in the topic Train A leaves New York at 9am Eastern Time on Monday Manaswita 3 10 Sep 2013, 04:39
38 Experts publish their posts in the topic Train A traveling at 60 m/hr leaves New York for Dallas at 6 carcass 13 31 Oct 2012, 03:26
94 Experts publish their posts in the topic Train A leaves New York for Boston at 3 PM and travels at rohitgoel15 34 21 Jul 2010, 23:49
Train A leaves the station at 5PM and travels North at the leeye84 5 13 Jul 2007, 11:19
Train A leaves New York for Boston at 3 PM and travels at kevincan 1 15 Sep 2006, 12:51
Display posts from previous: Sort by

Train A leaves New York for Boston at 3 PM and travels at

  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®.