Last visit was: 25 Apr 2024, 14:59 It is currently 25 Apr 2024, 14:59

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
avatar
VP
VP
Joined: 03 Feb 2003
Posts: 1012
Own Kudos [?]: 1629 [0]
Given Kudos: 0
Send PM
avatar
Manager
Manager
Joined: 26 Jan 2004
Posts: 212
Own Kudos [?]: 4 [0]
Given Kudos: 0
Location: India
Send PM
Joined: 31 Dec 1969
Own Kudos [?]: [0]
Given Kudos:
Concentration: Entrepreneurship, International Business
WE:Supply Chain Management (Energy and Utilities)
User avatar
Manager
Manager
Joined: 21 Mar 2004
Posts: 208
Own Kudos [?]: 744 [0]
Given Kudos: 0
Location: Cary,NC
Send PM
Re: At a certain race, two athlets run around a stadium. The [#permalink]
Alfred wrote:
This answer wworks for non integers too!

Speed 1 x time = distance 1
Speed 2 x time = distance 2
n = number of laps

distance 1 - distance 2 = 2 laps

so,

n x laps x 10 - n x laps x 6 = 2 laps (dividing by laps)

10n-6n = 2

4n = 2

n = 0.5 hours = 30 minutes



Your answer is a little confusing ( though I am not saying its wrong )
You define n = number of laps

and later say n = 30 mins which is the required time !!!

I think you might have missed something here :)

- ash
User avatar
Manager
Manager
Joined: 21 Mar 2004
Posts: 208
Own Kudos [?]: 744 [0]
Given Kudos: 0
Location: Cary,NC
Send PM
Re: At a certain race, two athlets run around a stadium. The [#permalink]
Here's my attempt.

let slower guy make n laps his vel = 1/10 lap/min

then,faster guy makes n+2 laps his vel = 1/6 lap/min

time taken for this is same for both guys.

n/ (1/10) = (n+2)/(1/6)

10n =6n+12

n=3 , slower guy makes 3 laps, takes 3*10 = 30 mins.

The LCM method is much quicker.
LCM of 6 and 10 gives the time when both guys meet at a point and complete an Integer number of laps.

The edit function has come back ......thank god...( or actually the programmer)

- ash
User avatar
CEO
CEO
Joined: 15 Dec 2003
Posts: 2709
Own Kudos [?]: 1537 [0]
Given Kudos: 0
Send PM
Re: At a certain race, two athlets run around a stadium. The [#permalink]
30 min.
difference b/w 1/6 and 1/10 is 1/15
1/15*X = 2
X = 30
User avatar
Manager
Manager
Joined: 21 Mar 2004
Posts: 208
Own Kudos [?]: 744 [0]
Given Kudos: 0
Location: Cary,NC
Send PM
Re: At a certain race, two athlets run around a stadium. The [#permalink]
I was wondering why I got a wrong answer using relative speed.

Initially,I was using relative speed as 10-6=4 ;-)
I declare myself a birdbrain !

Thanks Paul.
- ash
avatar
VP
VP
Joined: 03 Feb 2003
Posts: 1012
Own Kudos [?]: 1629 [0]
Given Kudos: 0
Send PM
Re: At a certain race, two athlets run around a stadium. The [#permalink]
My solution:

D1=D2+2 laps

T*1/6=T*1/10 + 2 (T is the time)

T=30



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
Re: At a certain race, two athlets run around a stadium. The [#permalink]
Moderators:
Math Expert
92915 posts
Senior Moderator - Masters Forum
3137 posts

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