It is currently 20 Jan 2018, 22:40

### 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

# M06-19

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 43334

Kudos [?]: 139624 [0], given: 12794

### Show Tags

15 Sep 2014, 23:27
Expert's post
22
This post was
BOOKMARKED
00:00

Difficulty:

55% (hard)

Question Stats:

57% (01:27) correct 43% (01:49) wrong based on 160 sessions

### HideShow timer Statistics

Buster leaves the trailer at noon and walks towards the studio at a constant rate of B miles per hour. 20 minutes later, Charlie leaves the same studio and walks towards the same trailer at a constant rate of C miles per hour along the same route as Buster. Will Buster be closer to the trailer than to the studio when he passes Charlie?

(1) Charlie gets to the trailer in 55 minutes.

(2) Buster gets to the studio at the same time as Charlie gets to the trailer.
[Reveal] Spoiler: OA

_________________

Kudos [?]: 139624 [0], given: 12794

Math Expert
Joined: 02 Sep 2009
Posts: 43334

Kudos [?]: 139624 [0], given: 12794

### Show Tags

15 Sep 2014, 23:27
Expert's post
3
This post was
BOOKMARKED
Official Solution:

(1) Charlie gets to the trailer in 55 minutes. No info about Buster. Not sufficient.

(2) Buster gets to the studio at the same time as Charlie gets to the trailer. Charlie needed 20 minutes less than Buster to cover the same distance, which means that the rate of Charlie is higher than that of Buster. Since after they pass each other they need the same time to get to their respective destinations (they get at the same time to their respective destinations) then Buster had less distance to cover ahead (at lower rate) than he had already covered (which would be covered by Charlie at higher rate). Sufficient.

_________________

Kudos [?]: 139624 [0], given: 12794

Manager
Joined: 10 Feb 2015
Posts: 119

Kudos [?]: 35 [0], given: 70

GMAT 1: 710 Q48 V38

### Show Tags

01 Aug 2015, 22:00
A very good question. You would just have to draw a straight line and think logically to solve this tricky problem.

Kudos [?]: 35 [0], given: 70

Manager
Joined: 12 Nov 2015
Posts: 60

Kudos [?]: 27 [0], given: 126

Location: Uruguay
Concentration: General Management
Schools: Goizueta '19 (A)
GMAT 1: 610 Q41 V32
GMAT 2: 620 Q45 V31
GMAT 3: 640 Q46 V32
GPA: 3.97

### Show Tags

27 Feb 2016, 08:35
Could we please expand on this answer, perhaps drawing a line to see how this works? Thank you

Kudos [?]: 27 [0], given: 126

Manager
Joined: 21 Jul 2014
Posts: 69

Kudos [?]: 12 [1], given: 59

Location: United States
WE: Project Management (Non-Profit and Government)

### Show Tags

31 May 2016, 07:58
1
KUDOS
VeritasPrepKarishma Bunuel

A-----------------X-----------------------------------------------------------------B

I have tried to visualize it this way. Say we have 100m distance between the two points. Now, See Buster has started 20 minutes before but still reaches at the same time that means his time is t + 20 if t is the time taken by charlie to reach 100 meters distance.

Now, one thing we know is that : charlie has higher speed than buster. So far so good. But how do we know what happens before they cross, at the time of crossing and after they have crossed is something I need more clarification on.

When Charlie starts Buster has already covered a distance equal to 20 times his speed in miles per hour. When charlie and Buster meet at say X point then we have D-X more than X Since if both we running at equal speed then starting 20 minutes early they would have met beyond the midpoint of the D.

I think, I am getting lost beyond this point.

Can you help me get organized from here?

Kudos [?]: 12 [1], given: 59

Math Expert
Joined: 02 Aug 2009
Posts: 5536

Kudos [?]: 6443 [2], given: 122

### Show Tags

31 May 2016, 08:23
2
KUDOS
Expert's post
ankushbagwale wrote:
VeritasPrepKarishma Bunuel

A-----------------X-----------------------------------------------------------------B

I have tried to visualize it this way. Say we have 100m distance between the two points. Now, See Buster has started 20 minutes before but still reaches at the same time that means his time is t + 20 if t is the time taken by charlie to reach 100 meters distance.

Now, one thing we know is that : charlie has higher speed than buster. So far so good. But how do we know what happens before they cross, at the time of crossing and after they have crossed is something I need more clarification on.

When Charlie starts Buster has already covered a distance equal to 20 times his speed in miles per hour. When charlie and Buster meet at say X point then we have D-X more than X Since if both we running at equal speed then starting 20 minutes early they would have met beyond the midpoint of the D.

I think, I am getting lost beyond this point.

Can you help me get organized from here?

Hi ankushbagwale and Avigano,

we are concerned what happens when B reaches half the distance..

B takes $$x$$ min and C takes $$x-20$$....
B is at half the distance at $$\frac{x}{2}$$.....

so lets see where is C at this time -20 min, as he starts 20 minutes later = $$\frac{x}{2} -20$$..
But when does C reach midway = at $$\frac{x-20}{2} =\frac{x}{2} - 10$$
since C reaches half way ONLY at $$\frac{x}{2} -10$$, he has to walk for another 10 minutes after $$\frac{x}{2}-20$$ to reach mid-way..
so they meet towards the starting point of C..
suff
_________________

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

BANGALORE/-

Kudos [?]: 6443 [2], given: 122

Manager
Joined: 21 Jul 2014
Posts: 69

Kudos [?]: 12 [0], given: 59

Location: United States
WE: Project Management (Non-Profit and Government)

### Show Tags

02 Jun 2016, 15:28
Thank you Chetan for your explanation. It all makes sense now. I think, logically also what bunuel said is the correct way. Suppose they were to meet at the middle point. Then in that case C would have reached the destination earlier that B. Suppose they meet at any point before the midpoint and towards B then C would have lesser distance and more rate than B, Hence C still would have reached before B. Thus, the only scenario when Both reaches at the same time is when B has already travelled considerable distance ( at least more than the half ) before C started and then C starts 20 minutes later and covers that at higher rate.

Kudos [?]: 12 [0], given: 59

Manager
Joined: 23 Apr 2014
Posts: 67

Kudos [?]: 9 [0], given: 82

Location: United States
GMAT 1: 680 Q50 V31
GPA: 2.75

### Show Tags

14 Jul 2016, 14:40
I think this is a high-quality question and I agree with explanation.

Kudos [?]: 9 [0], given: 82

Manager
Joined: 14 Oct 2012
Posts: 180

Kudos [?]: 64 [1], given: 966

### Show Tags

17 Apr 2017, 10:35
1
KUDOS
I wasn't satisfied with the explanation given here so i tried to solve it:
Smart numbers worked only after doing some attempts as answer used to vary with the distance between b mph and c mph. Let me know if you think i am doing some/anything wrong...

PLEASE USE C = 19 NOT 20.
as i said, the answer only made sense after a few trials...
>> !!!

You do not have the required permissions to view the files attached to this post.

Kudos [?]: 64 [1], given: 966

Intern
Joined: 30 Dec 2017
Posts: 6

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

### Show Tags

06 Jan 2018, 11:56
Is there a better explanation for this question? It looks like a good questions but the explanation is poorly written.

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

Math Expert
Joined: 02 Sep 2009
Posts: 43334

Kudos [?]: 139624 [0], given: 12794

### Show Tags

06 Jan 2018, 12:08
KillerGMAT wrote:
Is there a better explanation for this question? It looks like a good questions but the explanation is poorly written.

I think the explanation is fine. You can check other solution above.
_________________

Kudos [?]: 139624 [0], given: 12794

Re: M06-19   [#permalink] 06 Jan 2018, 12:08
Display posts from previous: Sort by

# M06-19

Moderators: chetan2u, Bunuel

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne 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®.