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

It is currently 19 Apr 2014, 07:49

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

how to solve this problem in 2 mins. any easy method?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
User avatar
Status: GMAT once done, Going for GMAT 2nd time.
Joined: 29 Mar 2010
Posts: 34
Location: Los Angeles, CA
Schools: Anderson, Haas, Ross, Kellog, Booth, McCombs
Followers: 0

Kudos [?]: 1 [0], given: 3

GMAT Tests User
how to solve this problem in 2 mins. any easy method? [#permalink] New post 18 Jul 2011, 13:09
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

50% (02:10) correct 50% (01:48) wrong based on 6 sessions
X is planning a bus trip across town that involves three buses. Bus 1 travels between house and downtown, and leaves every half-hour starting at 7:20am. X will need to be on Bus 1 for 1 1/5 hours. Bus 2 travels between downtown and uptown every half-hour starting at 7:10am. X will have to be on Bus 2 for 2/3 hour. Lastly, Bus 3 travels between uptown and destination every hour starting at 9 Am. what is the least total amount of time X wmust spend waiting for buses, assuming all buses stay on schedule?

A. 12 mins
B. 18 mins
C. 48 Mins
D. 1 hour 12 mins
E. 1 hour 20 mins
[Reveal] Spoiler: OA

_________________

BP

Manager
Manager
Joined: 20 Jan 2011
Posts: 88
Followers: 3

Kudos [?]: 35 [0], given: 23

GMAT Tests User
Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 18 Jul 2011, 15:10
Second bus service starts 10 mins earlier than first bus service and both have same frequency (every 30 mins). First bus take 1hr 12 mins.
Thus second bus one can get has waiting time 30 - (10+12)=8 mins
It is same always.
If you write time arrival time for first bus(8:32,9:02,9:32, add 30mins) and departure time for second bus(8:40,9:10,9:40 etc), you will get the same.

Similarly, third bus leaves every hour and service starts exactly on hour clock, a 10 mins early(7:10am and 9am, just mins since buses have frequency of either half or one hour)
Also second bus takes 2 hour 40 mins
Waiting time = 60-(10-40) =10 mins or 10+30=40 mins (since second bus leaves every 30 mins and third every 1hr)

First waiting time is always 8 mins, so take least time 10 mins for second waiting time.
Thus, least waiting time = 8+10 = 18 mins.

It did take more than 2 mins though.
_________________

Conquer the Hell and make it Haven. Brain is your hell and Success is your haven!

"Kudos" is significant part of GMAT prep. If you like it, you just click it :)

Intern
Intern
Joined: 18 Jun 2011
Posts: 14
WE: Information Technology (Investment Banking)
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 18 Jul 2011, 20:39
I am getting 48 mins as answer and this took 1.32 mins

For bus 2 is it 2/3 hour or the 2 2/3 of the hr, pls clarify.
Senior Manager
Senior Manager
User avatar
Joined: 03 Mar 2010
Posts: 446
Schools: Kelley,Tepper,Carlson,Kenan Flager,Broad
Followers: 3

Kudos [?]: 96 [0], given: 21

GMAT Tests User
Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 18 Jul 2011, 22:48
I am getting 48 mins too with 2nd Bus Travel time as 2/3 hour.
_________________

My dad once said to me: Son, nothing succeeds like success.

Current Student
Joined: 26 May 2005
Posts: 571
Followers: 18

Kudos [?]: 97 [0], given: 13

GMAT Tests User
Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 18 Jul 2011, 23:06
valencia wrote:
X is planning a bus trip across town that involves three buses. Bus 1 travels between house and downtown, and leaves every half-hour starting at 7:20am. X will need to be on Bus 1 for 1 1/5 hours. Bus 2 travels between downtown and uptown every half-hour starting at 7:10am. X will have to be on Bus 2 for 2/3 hour. Lastly, Bus 3 travels between uptown and destination every hour starting at 9 Am. what is the least total amount of time X wmust spend waiting for buses, assuming all buses stay on schedule?

A. 12 mins
B. 18 mins
C. 48 Mins
D. 1 hour 12 mins
E. 1 hour 20 mins


I go also go with C . 48 mints.. unless 2/3 reads as 7/6 in which case its 18 mints
Math Forum Moderator
Joined: 20 Dec 2010
Posts: 2058
Followers: 123

Kudos [?]: 827 [0], given: 376

GMAT Tests User
Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 18 Jul 2011, 23:31
valencia wrote:
X is planning a bus trip across town that involves three buses. Bus 1 travels between house and downtown, and leaves every half-hour starting at 7:20am. X will need to be on Bus 1 for 1 1/5 hours. Bus 2 travels between downtown and uptown every half-hour starting at 7:10am. X will have to be on Bus 2 for 2/3 hour. Lastly, Bus 3 travels between uptown and destination every hour starting at 9 Am. what is the least total amount of time X wmust spend waiting for buses, assuming all buses stay on schedule?

A. 12 mins
B. 18 mins
C. 48 Mins
D. 1 hour 12 mins
E. 1 hour 20 mins


I'd solve it like this:

1 starts at 7:20, 2@7:10, 3@9:00

Start after 9, no risks:

1: 9:20, 9:50, 10:20, 10:50, 11:20, 11:50, 12:20, 12:50, 1:20, 1:50
2: 9:10, 9:40, 10:10, 10:40, 11:10, 11:40, 12:10, 12:40, 1:10, 1:40
3: 9:00, 10:00, 11:00, 12:00, 1:00, 2:00

Test for two start time:

10:20 AND 10:50; One got to be correct

10:20
Travel: 72min
Arrive:11:32
Next:11:40(Wait=8)
Travel: 40min
Arrive:12:20
Next:1:00(Wait=40)
Total=48

10:50
Travel: 72min
Arrive:12:02
Next:12:10(Wait=8)
Travel: 40min
Arrive:12:50
Next:1:00(Wait=10)
Total=18

Ans: "B"
*******************
It will take about 2min to 2.25min max.
_________________

~fluke

Intern
Intern
Joined: 18 Jun 2011
Posts: 14
WE: Information Technology (Investment Banking)
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 19 Jul 2011, 00:39
So, we have to try 2 cenarois then, dint look at the Q stem, it states least wait time, how could one possibly think different.
Fluke - you are an eye opener
Thank You




Posted from iPhone 3GS

Posted from my mobile device Image
Manager
Manager
Joined: 24 Aug 2008
Posts: 233
Location: India
WE 1: 3.75 IT
WE 2: 1.0 IT
Followers: 2

Kudos [?]: 26 [0], given: 5

GMAT Tests User
Re: how to solve this problem in 2 mins. any easy method? [#permalink] New post 19 Jul 2011, 04:22
Fluke: Thanks for the explanation!! :-D
_________________

Cheers,
Varun


If you like my post, give me KUDOS!!

Re: how to solve this problem in 2 mins. any easy method?   [#permalink] 19 Jul 2011, 04:22
    Similar topics Author Replies Last post
Similar
Topics:
New posts Absolute Values - Problems and Method to solve tnttijji 4 22 Jul 2009, 06:46
New posts How to solve this question in 2min Viren 1 17 Sep 2009, 14:24
Moved topic Method & Technique To Solve Profit-Los Problems farukhawais 1 10 Jul 2010, 20:25
Popular new posts Struggling to solve DS problem in less than 2 min PadawanOfTheGMAT 11 20 Sep 2010, 06:45
New posts how to solve with martix method ITMRAHUL 5 08 Mar 2011, 08:53
Display posts from previous: Sort by

how to solve this problem in 2 mins. any easy method?

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.