A train traveled from Station A to Station B at an average speed of 80 : GMAT Data Sufficiency (DS)
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 10 Dec 2016, 07:25

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A train traveled from Station A to Station B at an average speed of 80

Author Message
TAGS:

### Hide Tags

Senior Manager
Joined: 29 Oct 2013
Posts: 297
Concentration: Finance
GMAT 1: 750 Q V46
GPA: 3.7
WE: Corporate Finance (Retail Banking)
Followers: 14

Kudos [?]: 365 [4] , given: 197

A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

04 Jun 2014, 23:00
4
KUDOS
11
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

64% (02:18) correct 36% (01:16) wrong based on 348 sessions

### HideShow timer Statistics

A train traveled from Station A to Station B at an average speed of 80 kilometers per hour and then from Station B to Station C at an average speed of 60 kilometers per hour. If the train did not stop at Station B, what was the average speed at which the train traveled from Station A to C?

(1) The distance that the train traveled from Station A to Station B was 4 times the distance that train traveled from Station B to Station C.
(2) The amount of time it took to the train to travel from Station A to Station B is 3 times the amount of time that it took the train to travel from Station B to Station C.

[Reveal] Spoiler:
Attachment:

Screen_Shot_2012_05_15_at_8_48_47_PM.png [ 29.93 KiB | Viewed 3922 times ]
[Reveal] Spoiler: OA

_________________

My journey V46 and 750 -> http://gmatclub.com/forum/my-journey-to-46-on-verbal-750overall-171722.html#p1367876

Last edited by Bunuel on 08 Jun 2015, 01:59, edited 2 times in total.
Renamed the topic and edited the question.
Senior Manager
Joined: 13 Jun 2013
Posts: 279
Followers: 13

Kudos [?]: 336 [0], given: 13

Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

05 Jun 2014, 00:29
2
This post was
BOOKMARKED
MensaNumber wrote:
A train traveled from station A to station B at an average speed of 80 kmph and then from Station B to Station C at an average speed of 60 kmph. What was the average speed from A to C?

1. The distance from A to C four times the distance from B to C
2. The amount of time it took to travel from A to B is four time that of time it took to travel from B to C

Kudos if you liked the question

Average speed = total distance/ total time.

1) A-----B-------C

let bc=x, therefore AC=4x, and AB=3x

thus average speed = 4x/{(3x/80)+(x/60)}

we can easily calculate the value of avg. speed from the above exp. hence sufficient

2) A---------B----------c

let distance between AB=x and BC=y
x/80=4(y/60)

x=(16/3)y-------------1)

average speed = x+y/{(x/80)+(y/60)}

we can substitute the value of x in terms of y in the above expression to find out the average speed. hence sufficient

therefore correct answer should be D
Intern
Joined: 02 Jan 2015
Posts: 33
GMAT Date: 02-08-2015
GPA: 3.7
WE: Management Consulting (Consulting)
Followers: 0

Kudos [?]: 15 [0], given: 54

Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

06 Jun 2015, 04:40
Is there a quicker way to see that the distance variable cancels out, rather than going through the entire algebraic calculation? I made the assumption that the variable would remain, and struggle to finish in ~ 2 minutes once I start getting into algebra for DS questions. Thanks..
Verbal Forum Moderator
Joined: 02 Aug 2009
Posts: 4148
Followers: 308

Kudos [?]: 3264 [1] , given: 100

Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

06 Jun 2015, 06:38
1
KUDOS
Expert's post
2
This post was
BOOKMARKED
ElCorazon wrote:
Is there a quicker way to see that the distance variable cancels out, rather than going through the entire algebraic calculation? I made the assumption that the variable would remain, and struggle to finish in ~ 2 minutes once I start getting into algebra for DS questions. Thanks..

Hi ElCorazon,
the Q stem tells us the speed in two different routes and asks us the average speed..
for this we require the distance or the ratio of distances..
lets see the statement..
1)statement 1 gives us the ratio of distance .. so sufficient..
2) statement two tells us the ratio of time so multiplying this ratio with speed would give us the ratio of distance .. again sufficient

ans D
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 8015
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Followers: 363

Kudos [?]: 2377 [3] , given: 163

Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

06 Jun 2015, 10:51
3
KUDOS
Expert's post
Hi ElCorazon,

The 'goal' to try to answer each Quant question in under 2 minutes is NOT practical. While some questions can be solved relatively quickly (in under 30 seconds), certain questions are designed to take longer to solve (upwards of 3 minutes, and that's if you KNOW what you're doing). These types of "multi-step trip" questions are usually wordier, take more steps to solve and require a higher degree of organization and attention-to-detail than most prompts, so it's understandable that you would need MORE than 2 minutes to solve it.

Instead of having a "2 minutes or less" goal, focus more on your overall efficiency - you should try to get this question correct without wasting time.

GMAT assassins aren't born, they're made,
Rich
_________________

# Rich Cohen

Co-Founder & GMAT Assassin

# Special Offer: Save $75 + GMAT Club Tests 60-point improvement guarantee www.empowergmat.com/ ***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*********************** Senior Manager Joined: 02 Dec 2014 Posts: 386 Location: Russian Federation Concentration: General Management, Economics GMAT 1: 640 Q44 V33 WE: Sales (Telecommunications) Followers: 0 Kudos [?]: 76 [0], given: 349 Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink] ### Show Tags 06 Jun 2015, 14:30 EMPOWERgmatRichC wrote: Hi ElCorazon, The 'goal' to try to answer each Quant question in under 2 minutes is NOT practical. While some questions can be solved relatively quickly (in under 30 seconds), certain questions are designed to take longer to solve (upwards of 3 minutes, and that's if you KNOW what you're doing). These types of "multi-step trip" questions are usually wordier, take more steps to solve and require a higher degree of organization and attention-to-detail than most prompts, so it's understandable that you would need MORE than 2 minutes to solve it. Instead of having a "2 minutes or less" goal, focus more on your overall efficiency - you should try to get this question correct without wasting time. GMAT assassins aren't born, they're made, Rich Hi Rich! I watched EMPOWERGmat course and you said that if we have a ratios that means that statement is sufficient. Hence answer is D. Do i think logically?=)) _________________ "Are you gangsters?" - "No we are Russians!" Veritas Prep GMAT Instructor Joined: 23 Oct 2013 Posts: 144 Followers: 26 Kudos [?]: 186 [1] , given: 9 Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink] ### Show Tags 07 Jun 2015, 16:11 1 This post received KUDOS Expert's post This question is not correct, because the statements conflict each other. It is impossible that, given A to B is 80 mph and B to C is 60 mph, both of these statements could be true. Think about this example: Statement 1 - assume distance from A to C is 320 miles. Because A to C is 4x B to C, then A to B is 3x B to C. Its a 3:1 ratio in the distances. Therefore we have 240 miles from A to B and 80 miles from B to C. That leaves us with time of 3 hours from A to B and time of 1 hour 20 minutes from B to C. Statement 2- this can't be possible given what we just figured out in statement 1. 3:1.33 does not equal 3:1. The question is flawed. _________________ Brandon Veritas Prep | GMAT Instructor If you found this post helpful, please give me kudos!!! Save$100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Math Expert
Joined: 02 Sep 2009
Posts: 35950
Followers: 6863

Kudos [?]: 90113 [0], given: 10417

Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

08 Jun 2015, 02:01
VeritasPrepBrandon wrote:
This question is not correct, because the statements conflict each other. It is impossible that, given A to B is 80 mph and B to C is 60 mph, both of these statements could be true. Think about this example:

Statement 1 - assume distance from A to C is 320 miles. Because A to C is 4x B to C, then A to B is 3x B to C. Its a 3:1 ratio in the distances. Therefore we have 240 miles from A to B and 80 miles from B to C. That leaves us with time of 3 hours from A to B and time of 1 hour 20 minutes from B to C.

Statement 2- this can't be possible given what we just figured out in statement 1. 3:1.33 does not equal 3:1.

The question is flawed.

Thank you for noticing this. Edited the question.
_________________
Manager
Joined: 26 Dec 2011
Posts: 123
Schools: HBS '18, IIMA
Followers: 0

Kudos [?]: 65 [2] , given: 44

Re: A train traveled from Station A to Station B at an average speed of 80 [#permalink]

### Show Tags

04 Jul 2016, 23:50
2
KUDOS
2
This post was
BOOKMARKED
NoHalfMeasures wrote:
A train traveled from Station A to Station B at an average speed of 80 kilometers per hour and then from Station B to Station C at an average speed of 60 kilometers per hour. If the train did not stop at Station B, what was the average speed at which the train traveled from Station A to C?

(1) The distance that the train traveled from Station A to Station B was 4 times the distance that train traveled from Station B to Station C.
(2) The amount of time it took to the train to travel from Station A to Station B is 3 times the amount of time that it took the train to travel from Station B to Station C.

[Reveal] Spoiler:
Attachment:
The attachment Screen_Shot_2012_05_15_at_8_48_47_PM.png is no longer available

The clear way to handle this answer -
Attachments

Untitled.jpg [ 58.85 KiB | Viewed 1577 times ]

_________________

Thanks,

Re: A train traveled from Station A to Station B at an average speed of 80   [#permalink] 04 Jul 2016, 23:50
Similar topics Replies Last post
Similar
Topics:
4 A certain train traveled from Station A to Station B. Was the train's 3 15 Aug 2016, 07:09
2 A train traveled from station X to station Y at a constant speed of 88 3 23 Jun 2016, 02:01
11 Trains A and B left stations R and S simultaneously on two s 6 08 Oct 2013, 07:24
5 Station Q is to the East of Station T. At 12 noon, a train s 6 30 Sep 2013, 10:45
2 Trains are leaving station A for station B every 15 minutes 7 26 Aug 2008, 08:43
Display posts from previous: Sort by