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

It is currently 02 Sep 2014, 23:38

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

Barry walks from one end to the other of a 30-meter long

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Intern
Intern
avatar
Joined: 05 Oct 2012
Posts: 10
Followers: 0

Kudos [?]: 6 [1] , given: 1

CAT Tests
Barry walks from one end to the other of a 30-meter long [#permalink] New post 20 Oct 2012, 09:12
1
This post received
KUDOS
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

58% (02:55) correct 42% (01:42) wrong based on 206 sessions
Barry walks from one end to the other of a 30-meter long moving walkway at a constant rate in 30 seconds, assisted by the walkway. When he reaches the end, he reverses direction and continues walking with the same speed, but this time it takes him 120 seconds because he is traveling against the direction of the moving walkway. If the walkway were to stop moving, how many seconds would it take Barry to walk from one end of the walkway to the other?

A) 48
B) 60
C) 72
D) 75
E) 80
[Reveal] Spoiler: OA
2 KUDOS received
Manager
Manager
User avatar
Joined: 08 Apr 2012
Posts: 129
Followers: 10

Kudos [?]: 56 [2] , given: 14

Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 20 Oct 2012, 11:55
2
This post received
KUDOS
nitzz wrote:
Barry walks from one end to the other of a 30-meter long moving walkway at a constant rate in 30 seconds, assisted by the walkway. When he reaches the end, he reverses direction and continues walking with the same speed, but this time it takes him 120 seconds because he is traveling against the direction of the moving walkway. If the walkway were to stop moving, how many seconds would it take Barry to walk from one end of the walkway to the other?

A) 48
B) 60
C) 72
D) 75
E) 80


Let Barry's speed be x m/s and walkway's speed by y m/s. We need to find 30/x.

If Barry walks in the direction of the moving walkway, the total speed is x + y. Time taken is 30/(x+y)
Thus, 30/(x+y) = 30

=> x + y = 1 ... (1)

If Barry walks against the moving walkway's direction, total speed is x-y. Time take is 30(x-y)
Thus, 30/(x-y) = 120

=> x - y = 1/4 ... (2)

Add (1) and (2),
=> 2x = 5/4
=> x = 5/8

therefore, 30/x = 48

Right answer is A.
_________________

Shouvik
http://www.Edvento.com
admin@edvento.com

Expert Post
6 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 25259
Followers: 3433

Kudos [?]: 25297 [6] , given: 2702

Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 22 Oct 2012, 06:10
6
This post received
KUDOS
Expert's post
nitzz wrote:
Barry walks from one end to the other of a 30-meter long moving walkway at a constant rate in 30 seconds, assisted by the walkway. When he reaches the end, he reverses direction and continues walking with the same speed, but this time it takes him 120 seconds because he is traveling against the direction of the moving walkway. If the walkway were to stop moving, how many seconds would it take Barry to walk from one end of the walkway to the other?

A) 48
B) 60
C) 72
D) 75
E) 80


Say Barry's speed is b meter per second and walkaway speed is w meter per second, then as Speed=\frac{Distance}{Time} we'll have that:

b+w=\frac{30}{30}=1;
b-w=\frac{30}{120}=\frac{1}{4};

Sum these two equations; 2b=\frac{5}{4} --> b=\frac{5}{8}.

Time=\frac{Distance}{Speed}=\frac{30}{(\frac{5}{8})}=48.

Answer: A.

Hope it 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

Intern
Intern
avatar
Joined: 31 Oct 2012
Posts: 24
Followers: 0

Kudos [?]: 1 [0], given: 4

Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 09 Dec 2012, 20:54
How do we know that it is b-w? Why cant it be w-b. The question never says anything about the speeds of b or w individually.
Expert Post
2 KUDOS received
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Preparing for the another shot...!
Joined: 03 Feb 2011
Posts: 1425
Location: India
Concentration: Finance, Marketing
GPA: 3.75
Followers: 127

Kudos [?]: 603 [2] , given: 62

GMAT ToolKit User GMAT Tests User Premium Member
Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 09 Dec 2012, 21:46
2
This post received
KUDOS
Expert's post
maddyboiler wrote:
How do we know that it is b-w? Why cant it be w-b. The question never says anything about the speeds of b or w individually.


If it is w-b, it means that speed of walkway is more than than his speed, then how will he reach the other end of the walkway.
_________________

Prepositional Phrases Clarified|Elimination of BEING| Absolute Phrases Clarified
Rules For Posting
www.Univ-Scholarships.com

Intern
Intern
avatar
Joined: 31 Oct 2012
Posts: 24
Followers: 0

Kudos [?]: 1 [0], given: 4

Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 10 Dec 2012, 05:41
Make sense, thanks.
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1631
Location: United States
Concentration: Finance
GMAT 1: 710 Q48 V39
WE: Corporate Finance (Investment Banking)
Followers: 11

Kudos [?]: 158 [0], given: 256

GMAT ToolKit User
Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 31 Dec 2013, 09:03
nitzz wrote:
Barry walks from one end to the other of a 30-meter long moving walkway at a constant rate in 30 seconds, assisted by the walkway. When he reaches the end, he reverses direction and continues walking with the same speed, but this time it takes him 120 seconds because he is traveling against the direction of the moving walkway. If the walkway were to stop moving, how many seconds would it take Barry to walk from one end of the walkway to the other?

A) 48
B) 60
C) 72
D) 75
E) 80



We have 30 (a+b) = 30
a+b = 1

We also get that 120 (a-b) = 30
So a-b = 1

So we have that a = 5/8

So 30*8/5 = 48

Answer is A

Hope it helps!
Cheers

J :)
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1631
Location: United States
Concentration: Finance
GMAT 1: 710 Q48 V39
WE: Corporate Finance (Investment Banking)
Followers: 11

Kudos [?]: 158 [0], given: 256

GMAT ToolKit User
Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 08 May 2014, 12:57
Let's try something else JFF ('Just for Fun')

B = Barry's Rate
W= Walkway's

So we have 30 (b+w) = 120 (b-w)
5w = 3b

D=30 (8/5b) = 48b

Time takes for Barry

t = D/R = 48b / b = 48 seconds

Answer: A
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1631
Location: United States
Concentration: Finance
GMAT 1: 710 Q48 V39
WE: Corporate Finance (Investment Banking)
Followers: 11

Kudos [?]: 158 [0], given: 256

GMAT ToolKit User
Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 20 May 2014, 05:48
Do we actually need to know that the distance is 30 meters?

IF we learn that w=3b/5 we can find distance in terms of 'b' and then divide by rate 'b' to figure out that it will take Ben 48 seconds to reach the end of the walkway

Please advice
Cheers!
J
Intern
Intern
avatar
Joined: 16 May 2014
Posts: 40
Followers: 0

Kudos [?]: 13 [0], given: 3

Re: Barry walks from one end to the other of a 30-meter long [#permalink] New post 20 May 2014, 06:03
jlgdr wrote:
Do we actually need to know that the distance is 30 meters?

IF we learn that w=3b/5 we can find distance in terms of 'b' and then divide by rate 'b' to figure out that it will take Ben 48 seconds to reach the end of the walkway

Please advice
Cheers!
J


No we don't need this value of 30 meters since the distance remains the same while travelling up and down and thus, speeds are inversely proportional to the time taken. The information is superfluous.


Hope it helps!!!
Re: Barry walks from one end to the other of a 30-meter long   [#permalink] 20 May 2014, 06:03
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic One hour before John started walking from P to Q, a distance tauchmeister 3 15 Apr 2014, 14:28
7 Experts publish their posts in the topic Happy end to the long journey from 570 to 730! nifoui 22 16 Aug 2010, 10:35
One hour after Yolanda started walking from X to Y, a alimad 3 13 Mar 2008, 18:15
One hour after Yolanda started walking from X to Y, a inwosu 2 22 Sep 2007, 11:13
1 One hour after Yolanda started walking from X to Y, a eleni24 4 05 Jan 2006, 16:41
Display posts from previous: Sort by

Barry walks from one end to the other of a 30-meter long

  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®.