Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 29 Nov 2015, 13:24

### 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

# Three friends-whose walking rates are .....

Author Message
TAGS:
Manager
Joined: 22 Sep 2010
Posts: 91
Followers: 1

Kudos [?]: 62 [0], given: 0

Three friends-whose walking rates are ..... [#permalink]  05 Oct 2010, 04:41
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 100% (00:58) wrong based on 2 sessions
Three friends-whose walking rates are 1 ft./sec., 3ft./sec.,and 6ft./sec. start together walking in the same direction around a circular track that is 300 feet in circumference.After how many minutes are the three of them together again?

A. 5 mins
B. 10 mins
C. 15 mins
D. 3 mins
E. 7 mins
Manager
Status: Will Retake GMAT
Joined: 29 Jul 2010
Posts: 137
Location: India
Concentration: General Management, Entrepreneurship
Schools: Stanford '13 (D)
GPA: 3.11
WE: Information Technology (Computer Software)
Followers: 3

Kudos [?]: 15 [0], given: 28

Re: Three friends-whose walking rates are ..... [#permalink]  05 Oct 2010, 05:13
Answer will be A. Whats the OA?

The time they take will be what the 1st friend takes to complete one circumference as he is the slowest and that is the point all 3 of them will be together at the end of 5mins.

Maybe someone can show this with a better explanation.
_________________

Re-taking GMAT. Hope the charm works this time..

Manager
Joined: 19 Jul 2009
Posts: 52
Location: baltimore, md
Schools: kellogg, booth, stern, ann arbor
Followers: 1

Kudos [?]: 28 [0], given: 3

Re: Three friends-whose walking rates are ..... [#permalink]  05 Oct 2010, 06:21
i got A as the answer. i set it up as follows

if A = 1ft/sec then with a distance of 300 ft, it would take A 300 seconds to complete
if B = 3ft/sec then with a distance of 300 ft, it would take B 100 seconds to complete
if C = 6ft/sec then with a distance of 300 ft, it would take C 50 seconds to complete

we can find the amount of time it would take for them to meet again by taking the LCM of the each of their times

the LCM of 300, 100, and 50 is 300. so 300 seconds converted to minutes is 5 minutes.

_________________

Paaaaayyy Meeeee!!!!!

Retired Moderator
Joined: 02 Sep 2010
Posts: 805
Location: London
Followers: 89

Kudos [?]: 682 [0], given: 25

Re: Three friends-whose walking rates are ..... [#permalink]  05 Oct 2010, 11:32
pzazz12 wrote:
Three friends-whose walking rates are 1 ft./sec., 3ft./sec.,and 6ft./sec. start together walking in the same direction around a circular track that is 300 feet in circumference.After how many minutes are the three of them together again?

A. 5 mins
B. 10 mins
C. 15 mins
D. 3 mins
E. 7 mins

Nice question !

To make this easier, you can assume that person 1 is standing still at the starting point and persons2 and 3 are moving at 2ft/sec and 5ft/sec
To satisfy the criterion of all three meeting, they would have to meet back at the start.
Person 2, does a circle every 300/2=150sec
So he will be at the start on these times {150,300,450,...}
Person 3 does the circle in 300/5=60sec
So he will be at the start at these times {60,120,180,240,300,....}

The least common time is 300sec or 5min

_________________
Re: Three friends-whose walking rates are .....   [#permalink] 05 Oct 2010, 11:32
Similar topics Replies Last post
Similar
Topics:
A man walks at a rate of 10 mph. After every ten miles, he 7 22 Jun 2014, 10:15
8 A man walking at a constant rate of 4 miles per hour is pass 6 18 Sep 2012, 11:43
39 A hiker walking at a constant rate of 4 miles per hour is pa 9 09 Nov 2010, 06:01
21 An absent minded scientist walks on an escalator at a rate 10 08 Nov 2010, 02:19
5 A hiker walking at a constant rate of 4 miles per hour is passed by a 8 14 Jun 2010, 05:24
Display posts from previous: Sort by