It is currently 12 Dec 2017, 19:49

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Mary passed a certain gas station on a highway while traveli

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Senior Manager
Senior Manager
User avatar
S
Joined: 24 Oct 2016
Posts: 317

Kudos [?]: 25 [0], given: 88

Location: India
Concentration: Finance, International Business
Schools: IIMB
GMAT 1: 550 Q42 V28
GPA: 3.96
WE: Human Resources (Retail Banking)
Re: Mary passed a certain gas station on a highway while traveli [#permalink]

Show Tags

New post 11 Feb 2017, 01:19
we can solve the above problem in just 15sec. if we look more closely to the problem as we can see that when they both meet they both have traveled the same distance so we do not need to calculate the distance , we know that when distance is constant then the speed is inversely proportional to the time, so form it we can calculate the speed is multiplied by 5/6 so no the time will multiplied by 6/5 and the difference between time between them equal to 15
such as : 6/5t-t=15
t=75 mins that equal to 1 hr.15 mins
hence the answer is D
thanks
if you liked my post please kudos :)

Kudos [?]: 25 [0], given: 88

Manager
Manager
avatar
B
Joined: 13 Dec 2013
Posts: 171

Kudos [?]: 29 [0], given: 122

Location: United States (NY)
Concentration: Nonprofit, International Business
GMAT 1: 710 Q46 V41
GMAT 2: 720 Q48 V40
GPA: 4
WE: Consulting (Consulting)
Reviews Badge
Re: Mary passed a certain gas station on a highway while traveli [#permalink]

Show Tags

New post 19 Mar 2017, 19:45
For me, there are two approaches to use.

1) Setting the time that Mary travels as t means that Paul travels for t-15 mins.
D=S*T and we want to find out when the distances from the station to the catch-up point are equal for both Mary and Paul.
60*(t-15)=50t
60t-900=50t
10t=900
t=90
Paul travels for 15mins less than Mary and so Paul's time is 75mins.

2) Using relative speeds we know that Paul's speed in comparison to Mary's speed is 10mph.
We need to know what distance Paul has to make up. Mary was travelling for 15mins before Paul arrived at the station and therefore traveled 50/4=12.5 miles. So, Paul will catch Mary up when he makes up the 12.5miles travelling at 10mph. T=D/S, 12.5/10=1.25h.

Kudos if you like the explanations. Also, please comment if you have alternative methods!

Kudos [?]: 29 [0], given: 122

Senior Manager
Senior Manager
avatar
B
Joined: 05 Jan 2017
Posts: 435

Kudos [?]: 63 [0], given: 15

Location: India
Premium Member
Re: Mary passed a certain gas station on a highway while traveli [#permalink]

Show Tags

New post 20 Mar 2017, 00:15
rags wrote:
Mary passed a certain gas station on a highway while traveling west at a constant speed of 50 miles per hour. Then, 15 minutes later, Paul passed the same gas station while traveling west at a constant speed of 60 miles per hour. If both drivers maintained their speeds and both remained on the highway for at least 2 hours, how long after he passed the gas station did Paul catch up with Mary?

A. 30 min
B. 45 min
C. 1 hr
D. 1 hr 15 min
E. 1 hr 30 min



after 15 minutes as paul is passing the gas station, Mast will be 50 *15/60 = 12.5 miles away
relative speed since they are moving in same direction will be 60 - 50 =10 mph

time taken to cover 12.5 miles = 12.5/10 = 1.25 hours = 1 hour 15 minute

Option D

Kudos [?]: 63 [0], given: 15

Manager
Manager
User avatar
B
Status: IF YOU CAN DREAM IT, YOU CAN DO IT
Joined: 03 Jul 2017
Posts: 177

Kudos [?]: 8 [0], given: 14

Location: India
Concentration: Finance, International Business
Mary passed a certain gas station on a highway while traveli [#permalink]

Show Tags

New post 11 Aug 2017, 00:28
So the speed of Mary is 50m/h and speed of Paul is 60m/hr . Also Paul travels for 15 minutes more than Mary. So the distance between the distance between the gas station and the meeting point is d and the relative speed is 60-50=10mh/hr
Can someone assist me after these steps. Thank you.

Kudos [?]: 8 [0], given: 14

Intern
Intern
User avatar
B
Joined: 16 Jul 2011
Posts: 46

Kudos [?]: 3 [0], given: 165

Concentration: Marketing, Real Estate
GMAT 1: 550 Q37 V28
GMAT 2: 610 Q43 V31
Reviews Badge
Re: Mary passed a certain gas station on a highway while traveli [#permalink]

Show Tags

New post 11 Oct 2017, 11:03
Mary had started 15 mins before @ 50m/hr. Hence she had already covered 12.5m before Paul started. Hence the Paul has to cover 12.5m + the distance Mary is going to cover before he meets her. Let x be the time at which they both meet. Therefore the equation will be:
\(12.5 + 50x = 60x\)
-->\(10x = 12.5\)
-->\(x = 1.25\) i.e. 1 hr 15 mins.
_________________

"The fool didn't know it was impossible, so he did it."

Kudos [?]: 3 [0], given: 165

Intern
Intern
User avatar
B
Joined: 16 Mar 2017
Posts: 9

Kudos [?]: 5 [0], given: 99

GPA: 3.87
Re: Mary passed a certain gas station on a highway while traveli [#permalink]

Show Tags

New post 23 Oct 2017, 01:16
A )At t=30
Mary: 25 miles Paul: 15 miles

B) At t= 45
Mary: 37,5 Paul: 30 miles

C) At t=1 hr
Mary: 50 Paul:45 miles

D) At t=1 hr 15
Mary: 62,5 Paul: 60

E) At t=1h30
Mary: 75 miles Paul: 75 miles

It seems like E is the answer. What is wrong with my line of reasoning? Would appreciate your help
_________________

Lina

Kudos [?]: 5 [0], given: 99

Re: Mary passed a certain gas station on a highway while traveli   [#permalink] 23 Oct 2017, 01:16

Go to page   Previous    1   2   3   [ 46 posts ] 

Display posts from previous: Sort by

Mary passed a certain gas station on a highway while traveli

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.