Register    Login    Search    Rss Feeds

Forums Home » Ask An Instructor » GMAT Math » GMAT Prep Math


 Page 1 of 1 [ 2 posts ] 



  Print view Print view Previous topic Previous topic | Next topic Next topic
 

A hiker walking at a constant rate

Author Message
agha79
 Post subject: A hiker walking at a constant rate
 Post Posted: Tue Feb 22, 2011 2:51 pm 
Offline
Course Students


Posts: 98
A hiker walking at a constant rate of 4 miles per hour is passed by a cyclist traveling in the same direction along the same path at a constant rate of 20 miles per hour. The cyclist stops to wait for the hiker 5 minutes after passing her, while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?

A. 6 2/3
B. 15
C. 20
D. 25
E. 26 2/3

Rate of hiker in minutes=1/15 miles per minute
Rate of cyclist in minutes=1/3 miles per minute
Cyclist in 5 minutes traveled distance of 5/3 miles (1/3*5)
Hiker travels the same distance in 25 minutes (5*15/3)
So I choose D.

But OA is C.

As the hiker continues to walk while cyclist has crossed her make us deduct the time took by the cyclist to reach at the stopping point. 25-5=20. Is it the rationale behind the actual answer or I made some mistake in calculations?
Top 
RonPurewal
 Post subject: Re: A hiker walking at a constant rate
 Post Posted: Thu Feb 24, 2011 3:06 am 
Offline
ManhattanGMAT Staff


Posts: 7146
agha79 wrote:
As the hiker continues to walk while cyclist has crossed her make us deduct the time took by the cyclist to reach at the stopping point. 25-5=20. Is it the rationale behind the actual answer or I made some mistake in calculations?


yes, that's the rationale.
i.e., you weren't reading the problem carefully enough at first -- the problem statement very clearly asks how long the cyclist must wait; the cyclist doesn't start “waiting” until he/she has stopped.
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 2 posts ] 





Who is online

Users browsing this forum: No registered users and 0 guests

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: