Last visit was: 25 Apr 2026, 23:43 It is currently 25 Apr 2026, 23:43
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.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 25 Apr 2026
Posts: 109,830
Own Kudos:
Given Kudos: 105,887
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,830
Kudos: 811,313
 [23]
1
Kudos
Add Kudos
22
Bookmarks
Bookmark this Post
User avatar
nick1816
User avatar
Retired Moderator
Joined: 19 Oct 2018
Last visit: 12 Mar 2026
Posts: 1,841
Own Kudos:
8,511
 [3]
Given Kudos: 707
Location: India
Posts: 1,841
Kudos: 8,511
 [3]
3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 25 Apr 2026
Posts: 22,286
Own Kudos:
26,537
 [1]
Given Kudos: 302
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 22,286
Kudos: 26,537
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
effatara
Joined: 09 Nov 2015
Last visit: 17 Jul 2024
Posts: 194
Own Kudos:
Given Kudos: 96
Posts: 194
Kudos: 476
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Assume John and Carsten meet at point M and they take 't' hrs to reach B and A respectively. So the times taken by John and Carsten to cover AB are (t+9) and (t+4) hrs respectively. The ratio of their speeds is the inverse of the times taken by each to cover AB:
John's speed/Carsten's speed = (t+4)/(t+9)
The times taken by John and Carsten to cover MB is 't' and 4 hrs respectively. T/4:
John's speed/Carsten's speed = 4/t. T/4:
(t+4)/(t+9) = 4/t....> t^2 = 36....> t = 6
They reach their respective destinations at 6:30. ANS: B
User avatar
Gemmie
Joined: 19 Dec 2021
Last visit: 17 Apr 2026
Posts: 484
Own Kudos:
Given Kudos: 76
Location: Viet Nam
Concentration: Technology, Economics
GMAT Focus 1: 695 Q87 V84 DI83
GPA: 3.55
GMAT Focus 1: 695 Q87 V84 DI83
Posts: 484
Kudos: 490
Kudos
Add Kudos
Bookmarks
Bookmark this Post
­John's speed: a
Carsten's speed: b

3:30 am: John starts
8:30 am (5 hours later): Carsten starts
12:30 pm (4 hours later): They meet
After that, it take them the same time (t hours) to reach their destination

=> 9a + 4b = (9+t) * a = (4+t) * b
=> 9a + 4b = 9a + ta = 4b + tb
=> \(4b = ta => t = \frac{4b}{a}\)
      \(9a = tb => t = \frac{9a}{b}\)
=> \(t^2 = \frac{4b}{a} * \frac{9a}{b} = 36\)
=> t = 6 (hours)

=> They reach their destination at 6:30 pm
      ­
User avatar
DmitryFarberMPrep
User avatar
Manhattan Prep Instructor
Joined: 22 Mar 2011
Last visit: 03 Mar 2026
Posts: 3,005
Own Kudos:
8,627
 [2]
Given Kudos: 57
Expert
Expert reply
GMAT Focus 1: 745 Q86 V90 DI85
Posts: 3,005
Kudos: 8,627
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Great solutions, all, but the question does need a slight correction. It ought to state that both drivers are moving at a constant rate. Otherwise, we have no idea when they get anywhere! :) I know that's picky, but when you deal with DS and other DI section issues of "can I even solve this?" it's important to hold out for those details. As written, this question has no answer!
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,987
Own Kudos:
Posts: 38,987
Kudos: 1,118
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109830 posts
Tuck School Moderator
852 posts