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

It is currently 29 Aug 2014, 20:23

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

a train crosses a bridge in 5a seconds and crosses anotherr

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
User avatar
Joined: 07 Jul 2005
Posts: 406
Location: Sunnyvale, CA
Followers: 2

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

GMAT Tests User
a train crosses a bridge in 5a seconds and crosses anotherr [#permalink] New post 23 Jun 2006, 15:45
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 sessions
a train crosses a bridge in 5a seconds and crosses anotherr train of

length equal to that of the bridge and moving in opp: dirn: in 4a

secs.if train overtakes the other train when moving in same directio

in 240 secs,what is value of 'a'?


I don't have answer choices but thought it might be an interesting question to solve.
Director
Director
avatar
Joined: 16 Aug 2005
Posts: 950
Location: France
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
Re: PS : Train [#permalink] New post 23 Jun 2006, 19:27
sgrover wrote:
a train crosses a bridge in 5a seconds and crosses anotherr train of length equal to that of the bridge and moving in opp: dirn: in 4a secs.if train overtakes the other train when moving in same direction in 240 secs,what is value of 'a'?

I don't have answer choices but thought it might be an interesting question to solve.

Ok here I go:
Let D be the length of the bridge and the second train

S1 = D/5a
S3 = S1 + S2 = D/4a

Therefore, speed of second train (S2) = S3 - S1 = D/20

Also, S2 - S1 = D/240
S1 = D/20 - D/240 = 11D/240
a = 48/11 .... phew!

This question was more Kaplan-like than Gmat-like. Dont even know if I made a mistake here...please review!
_________________

I believe its yogurt!

Manager
Manager
avatar
Joined: 01 Jun 2006
Posts: 142
Followers: 1

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

Re: PS : Train [#permalink] New post 23 Jun 2006, 20:13
[quote="gmatmba"][quote="sgrover"]a train crosses a bridge in 5a seconds and crosses anotherr train of length equal to that of the bridge and moving in opp: dirn: in 4a secs.if train overtakes the other train when moving in same direction in 240 secs,what is value of 'a'?

I don't have answer choices but thought it might be an interesting question to solve.[/quote]
Ok here I go:
Let D be the length of the bridge and the second train

S1 = D/5a
S3 = S1 + S2 = D/4a

Therefore, speed of second train (S2) = S3 - S1 = D/20

Also, S2 - S1 = D/240
S1 = D/20 - D/240 = 11D/240
a = 48/11 .... phew!

This question was more Kaplan-like than Gmat-like. Dont even know if I made a mistake here...please review![/quote]


S2= S3-S1= D/20a
I think we got S1 - S2= D/240
So D/5a - D/20a = D/240 => a=36
Director
Director
User avatar
Joined: 06 May 2006
Posts: 783
Followers: 3

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

GMAT Tests User
 [#permalink] New post 24 Jun 2006, 10:21
V1 = d/5a
V1+V2=d/4a
V1-V2=d/240

=> (1/4a)-(1/240)=2/5a => a=36
Senior Manager
Senior Manager
avatar
Joined: 16 Apr 2006
Posts: 280
Followers: 2

Kudos [?]: 21 [0], given: 2

GMAT Tests User
 [#permalink] New post 24 Jun 2006, 21:50
Speed be S1, s2
Length of bridge = L
Time Taken a, 4a

S1*5a = L = (s1+s2)*4a
(s1-s2)*240 = L

S1a = 4a*s2
S1 = 4*S2

3S2*240 = 20as2
a = 36
  [#permalink] 24 Jun 2006, 21:50
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic The government’s design for the new cross-state bridge dqtuan9627 6 08 May 2014, 05:11
The toll for crossing a certain bridge is $0.75 each albany09 4 09 Oct 2008, 05:00
The toll for crossing the bridge is $0.75 each crossing. puma 2 01 May 2008, 20:28
The toll for crossing a certain bridge is $0.75 each dinesh8 3 02 May 2006, 02:11
A train crosses a bridge of length 500m in 40 seconds and a cloaked_vessel 9 05 Mar 2005, 21:35
Display posts from previous: Sort by

a train crosses a bridge in 5a seconds and crosses anotherr

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.