NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 17:12 It is currently 26 Apr 2024, 17:12
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

Train A leaves on schedule every 34 minutes and Train B leaves on sche

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92948
Own Kudos [?]: 619244 [2]
Given Kudos: 81609
Send PM
CAT Tests Forum Quiz Mode
Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink] New post   08 Dec 2016, 14:08
1
Kudos
1
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

25% (medium)

Question Stats:

75% (01:23) correct 25% (01:28) wrong based on 122 sessions
Hide Show timer Statistics
Train A leaves on schedule every 34 minutes and Train B leaves on schedule every 30 minutes. If both trains just left the station simultaneously, how long until the next time the two trains will leave simultaneously?

A. 64 minutes
B. 170 minutes
C. 340 minutes
D. 510 minutes
E. 1020 minutes
ShowHide Answer
Official Answer
D
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18767
Own Kudos [?]: 22065 [1]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink] New post   12 Dec 2016, 18:01
1
Kudos
Expert Reply
Bunuel wrote:
Train A leaves on schedule every 34 minutes and Train B leaves on schedule every 30 minutes. If both trains just left the station simultaneously, how long until the next time the two trains will leave simultaneously?

A. 64 minutes
B. 170 minutes
C. 340 minutes
D. 510 minutes
E. 1020 minutes


The LCM can be used to determine when two processes that occur at differing rates or times will coincide. Since we are given that Train A leaves a station every 34 minutes and Train B leaves every 30 minutes, we need to determine the LCM of 34 and 30. Let’s first prime factorize 34 and 30.

34 = 2 x 17

30 = 2 x 3 x 5

To determine the LCM we multiply the each unique prime factor of the largest power.

Thus, the LCM is 2 x 3 x 5 x 17 = 30 x 17 = 510.

Answer: D
User avatar
L
rohit8865
Director
Director
Joined: 05 Mar 2015
Posts: 852
Own Kudos [?]: 861 [1]
Given Kudos: 45
Send PM
Reviews Badge
Re: Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink] New post   08 Dec 2016, 19:27
1
Bookmarks
Bunuel wrote:
Train A leaves on schedule every 34 minutes and Train B leaves on schedule every 30 minutes. If both trains just left the station simultaneously, how long until the next time the two trains will leave simultaneously?

A. 64 minutes
B. 170 minutes
C. 340 minutes
D. 510 minutes
E. 1020 minutes



LCM(30,34) =510

Ans D
avatar
Bani
Intern
Intern
Joined: 24 Nov 2013
Posts: 5
Own Kudos [?]: 5 [0]
Given Kudos: 15
Concentration: Marketing, Strategy
GPA: 3.4
WE:Information Technology (Computer Software)
Send PM
Re: Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink] New post   08 Dec 2016, 23:00
time should be equal

30*x1 = 34*x2
=>x1/x2 = 34/30 = 17/15 (ratio)

1st time the trains would run simultaneously is :30*17 = 34*15 = 510
second time: ratio *2 = 34/30 => 30 *34 = 34*30 = 1020
so on and so forth...
avatar
S
RR88
Manager
Manager
Joined: 18 Oct 2016
Posts: 112
Own Kudos [?]: 141 [0]
Given Kudos: 91
Location: India
WE:Engineering (Energy and Utilities)
Send PM
Re: Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink] New post   09 Dec 2016, 00:24
Option D)

Train A leaves at every 34 minutes
Train B leaves at every 30 minutes

Given that these two trains leave simultaneously, the next time these two trains will get to leave simultaneously will be after [LCM (34,30)] minutes, i.e., 510 minutes
User avatar
S
TheGuyDangerous
Current Student
Joined: 10 Sep 2019
Posts: 137
Own Kudos [?]: 33 [0]
Given Kudos: 59
Location: India
Concentration: Social Entrepreneurship, Healthcare
Schools: Fuqua '24 (D) ISB '23 (A) Darden '24 (D) Johnson '24 (D) Kenan-Flagler '24 (I) McDonough '24 (S) Tepper '24 (S)
GMAT 1: 680 Q49 V33
GMAT 2: 720 Q50 V37
GRE 1: Q167 V159
GPA: 2.59
WE:Project Management (Non-Profit and Government)
Send PM
Reviews Badge
Re: Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink] New post   20 Nov 2019, 05:04
For them to simultaneously, they should leave at every LCM (A, B) min.

LCM (34,30) = 34*15 = 510 min

Ans D
GMAT Club Bot
gmatclubot
Re: Train A leaves on schedule every 34 minutes and Train B leaves on sche [#permalink]
20 Nov 2019, 05:04
Moderators:
Bunuel
Math Expert
92948 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions