 It is currently 24 Mar 2019, 23:27 ### 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

#### Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here. # Running on a 10-mile loop in the same direction, Sue ran at  Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Intern Joined: 13 Mar 2018
Posts: 13
Followers: 0

Kudos [?]: 2 , given: 0

Running on a 10-mile loop in the same direction, Sue ran at [#permalink] 00:00

Question Stats: 70% (01:06) correct 30% (01:30) wrong based on 20 sessions
Running on a 10-mile loop in the same direction, Sue ran at a constant rate of 8 miles per hour and Rob ran at a constant rate of 6 miles per hour. If they began running at the same point on the loop, how many hours later did Sue complete exactly 1 more lap than Rob?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7
[Reveal] Spoiler: OA

Last edited by Carcass on 14 Mar 2018, 12:53, edited 1 time in total.
Edited by Carcass GRE Prep Club Legend  Joined: 07 Jun 2014
Posts: 4857
GRE 1: Q167 V156 WE: Business Development (Energy and Utilities)
Followers: 105

Kudos [?]: 1783  , given: 397

1
KUDOS
Expert's post
Shrija Roy wrote:
2. Running on a 10-mile loop in the same direction, Sue ran at a constant rate of 8 miles per hour and Rob ran at a
constant rate of 6 miles per hour. If they began running at the same point on the loop, how many hours later did
Sue complete exactly 1 more lap than Rob?
(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

Rewriting the question: How many hours later was Sue 10 miles ahead of Rob.

Say this happens x hours later.

So;
distance covered by Sue in x hours -distance covered by Rob in x hours = 10 miles

or $$8 \times x - 6 \times x =10$$. Solving for x; $$x=5$$ hours.

Hence option C is correct!
_________________

Sandy
If you found this post useful, please let me know by pressing the Kudos Button

Try our free Online GRE Test

Intern Joined: 13 Mar 2018
Posts: 13
Followers: 0

Kudos [?]: 2 , given: 0

Sorry, one question here -

Sue has a speed of 8m/hr and Rob has the speed of 6 m/hr. So how are we taking the same x time?
Ideally, speed is inversely proportional to time so Sue should complete the lap early, no? Director  Joined: 07 Jan 2018
Posts: 604
Followers: 7

Kudos [?]: 546  , given: 88

Re: Running on a 10-mile loop in the same direction, Sue ran at [#permalink]
2
KUDOS
For every hour sue has a lead of $$\frac{2miles}{hr}$$ over Rob.
To get an exact 1 lap lead sue has to have total lead of $$10$$ miles as the lap is 10 miles long
Hence $$\frac{10}{2} = 5$$. Time that is required to put a one lap lead on Rob
option c
_________________

This is my response to the question and may be incorrect. Feel free to rectify any mistakes Target Test Prep Representative Status: Head GRE Instructor
Affiliations: Target Test Prep
Joined: 09 May 2016
Posts: 161
Location: United States
Followers: 4

Kudos [?]: 125  , given: 0

Re: Running on a 10-mile loop in the same direction, Sue ran at [#permalink]
1
KUDOS
Expert's post
Shrija Roy wrote:
Running on a 10-mile loop in the same direction, Sue ran at a constant rate of 8 miles per hour and Rob ran at a constant rate of 6 miles per hour. If they began running at the same point on the loop, how many hours later did Sue complete exactly 1 more lap than Rob?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

When Sue completes exactly 1 more lap than Rob, she will have traveled exactly 10 miles more than Rob (since the loop is 10 miles long). We can let both of the times = t and create the equation:

8t = 6t + 10

2t = 10

t = 5

_________________

GRE Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions GRE Instructor Joined: 10 Apr 2015
Posts: 1543
Followers: 56

Kudos [?]: 1468  , given: 8

Re: Running on a 10-mile loop in the same direction, Sue ran at [#permalink]
1
KUDOS
Expert's post
Shrija Roy wrote:
Running on a 10-mile loop in the same direction, Sue ran at a constant rate of 8 miles per hour and Rob ran at a constant rate of 6 miles per hour. If they began running at the same point on the loop, how many hours later did Sue complete exactly 1 more lap than Rob?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

1 lap = 10 miles
So, if Sue completes 1 lap more than Rob completes, then we know that Sue has traveled 10 miles more than Rob

So, let's start with a word equation:
(Sue's travel distance) = (Rob's travel distance) + 10 miles

Distance = (speed)(time)
We know each person's speed, but we don't know their travel times.
Let t = Sue's travel time
So, t = Rob's travel time also

Now take our word equation and plug in the necessary values:
10t = 8t + 10
Solve to get: t = 5

RELATED VIDEO

_________________

Brent Hanneson – Creator of greenlighttestprep.com Sign up for our free GRE Question of the Day emails

Intern Joined: 13 Mar 2018
Posts: 13
Followers: 0

Kudos [?]: 2 , given: 0

Re: Running on a 10-mile loop in the same direction, Sue ran at [#permalink]
I still have not been able to understand why the time would taken the same for both Sue and Rob, could anybody kindly advise?
GRE Instructor Joined: 10 Apr 2015
Posts: 1543
Followers: 56

Kudos [?]: 1468 , given: 8

Re: Running on a 10-mile loop in the same direction, Sue ran at [#permalink]
Expert's post
Shrija Roy wrote:
I still have not been able to understand why the time would taken the same for both Sue and Rob, could anybody kindly advise?

They both started running at the same time, and we stopped the clock (for both runners) once Sue lapped Rob.

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com Sign up for our free GRE Question of the Day emails GRE Instructor Joined: 10 Apr 2015
Posts: 1543
Followers: 56

Kudos [?]: 1468  , given: 8

Re: Running on a 10-mile loop in the same direction, Sue ran at [#permalink]
1
KUDOS
Expert's post
Shrija Roy wrote:
Running on a 10-mile loop in the same direction, Sue ran at a constant rate of 8 miles per hour and Rob ran at a constant rate of 6 miles per hour. If they began running at the same point on the loop, how many hours later did Sue complete exactly 1 more lap than Rob?

(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

As I mention in the video below, we can often solve these kinds of problems using more than 1 approach.
So, instead of comparing distances (as I did above), let's compare times

Our word equation can be: Sue's travel time = Rob's travel time

Let x = the distance Rob traveled
We know that Sue traveled ONE LAP more than Rob traveled. Since 1 lap = 10 miles, we know that Sue traveled 10 miles MORE THAN Rob.
This means x + 10 = the distance Sue traveled

time = distance/speed
So, our word equation becomes: (x + 10)/8 = x/6
Cross multiply to get: 6(x + 10) = 8(x)
Expand to get: 6x + 60 = 8x
We get: 60 = 2x
So, x = 30

This means ROB traveled 30 miles (and it means SUE traveled 40 miles)

If they began running at the same point on the loop, how many hours later did Sue complete exactly 1 more lap than Rob?
time = distance/speed
Let's use Rob's distance and speed to get: time = 30/6 = 5 hours

RELATED VIDEO FROM OUR COURSE

_________________

Brent Hanneson – Creator of greenlighttestprep.com Sign up for our free GRE Question of the Day emails Re: Running on a 10-mile loop in the same direction, Sue ran at   [#permalink] 19 Dec 2018, 09:20
Display posts from previous: Sort by

# Running on a 10-mile loop in the same direction, Sue ran at  Question banks Downloads My Bookmarks Reviews Important topics Powered by phpBB © phpBB Group Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.