It is currently 15 Dec 2017, 02:26

Decision(s) Day!:

CHAT Rooms | Wharton R1 | Stanford R1 | Tuck R1 | Ross R1 | Haas R1 | UCLA R1


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

Mr Ben leaves his house for work at exactly 8:00 AM every mo

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

Hide Tags

2 KUDOS received
Director
Director
avatar
Joined: 29 Nov 2012
Posts: 862

Kudos [?]: 1489 [2], given: 543

Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 11 Sep 2013, 01:23
2
This post received
KUDOS
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

68% (02:43) correct 32% (01:58) wrong based on 201 sessions

HideShow timer Statistics

Mr Ben leaves his house for work at exactly 8:00 AM every morning. When he averages 40 miles per hour, he arrives at his workplace three minutes late. When he averages 60 miles per hour, he arrives three minutes early. At what average speed, in miles per hour, should Mr. Ben drive to arrive at his workplace precisely on time?

A) 45
B) 48
C) 50
D) 55
E) 58

[Reveal] Spoiler:
Here is what I did

\(\frac{D}{40} - \frac{3}{60} = \frac{D}{60} + \frac{3}{60}\)

Solve this equation to get

\(D = 12\)

\(\frac{D}{40} - \frac{3}{60}\) ( will this equation give me the time?)

we get \(\frac{1}{4}\)

R * T = D

\(\frac{1}{4} * X = 12\)

X = 48

Is this correct?
[Reveal] Spoiler: OA

_________________

Click +1 Kudos if my post helped...

Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/

GMAT Prep software What if scenarios http://gmatclub.com/forum/gmat-prep-software-analysis-and-what-if-scenarios-146146.html

Kudos [?]: 1489 [2], given: 543

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42620

Kudos [?]: 135696 [1], given: 12706

Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 11 Sep 2013, 01:33
1
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
fozzzy wrote:
Mr Ben leaves his house for work at exactly 8:00 AM every morning. When he averages 40 miles per hour, he arrives at his workplace three minutes late. When he averages 60 miles per hour, he arrives three minutes early. At what average speed, in miles per hour, should Mr. Ben drive to arrive at his workplace precisely on time?

A) 45
B) 48
C) 50
D) 55
E) 58

Here is what I did

\(\frac{D}{40} - \frac{3}{60} = \frac{D}{60} + \frac{3}{60}\)

Solve this equation to get

\(D = 12\)

\(\frac{D}{40} - \frac{3}{60}\) ( will this equation give me the time?)

we get \(\frac{1}{4}\)

R * T = D

\(\frac{1}{4} * X = 12\)

X = 48

Is this correct?


Yes, that's correct. From D=12 miles, you can get the time T in which he should get to the work (T=D/40-3/60) and then the required rate (R=D/T=12/(1/4)=48 miles).
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135696 [1], given: 12706

Intern
Intern
avatar
Joined: 23 Mar 2011
Posts: 40

Kudos [?]: 13 [0], given: 21

Location: India
Concentration: Marketing, Operations
Schools: Schulich '16 (A)
GMAT 1: 690 Q48 V36
WE: Operations (Telecommunications)
Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 11 Sep 2013, 01:45
fozzzy wrote:
Mr Ben leaves his house for work at exactly 8:00 AM every morning. When he averages 40 miles per hour, he arrives at his workplace three minutes late. When he averages 60 miles per hour, he arrives three minutes early. At what average speed, in miles per hour, should Mr. Ben drive to arrive at his workplace precisely on time?

A) 45
B) 48
C) 50
D) 55
E) 58

[Reveal] Spoiler:
Here is what I did

\(\frac{D}{40} - \frac{3}{60} = \frac{D}{60} + \frac{3}{60}\)

Solve this equation to get

\(D = 12\)

\(\frac{D}{40} - \frac{3}{60}\) ( will this equation give me the time?)

we get \(\frac{1}{4}\)

R * T = D

\(\frac{1}{4} * X = 12\)

X = 48

Is this correct?


I too followed the same approach. Here 8AM is an extra information.

Let the distance from house to work be x
& the right time required to reach office on time be t.

At 40 miles/hr, he is 3 minutes late from time
therefore,\(\frac{x}{40}\) = t + \(\frac{3}{60}\)

At 60 miles/hr, he is 3 minutes early
i.e. \(\frac{x}{60}\) = t - \(\frac{3}{60}\)

Now, either you equate t or subtract one equation from another,
you will get x=12

Now find t, putting x in any equation
\(\frac{12}{60}\)=t - \(\frac{3}{60}\)

t will come out to be, t = \(\frac{1}{4}\)

So Average speed to reach office precisely on time = \(\frac{x}{t}\) =\(\frac{12}{(1/4)}\) = 12*4 = 48

Ans B

Kudos [?]: 13 [0], given: 21

Intern
Intern
avatar
Joined: 23 Mar 2011
Posts: 40

Kudos [?]: 13 [0], given: 21

Location: India
Concentration: Marketing, Operations
Schools: Schulich '16 (A)
GMAT 1: 690 Q48 V36
WE: Operations (Telecommunications)
Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 11 Sep 2013, 01:56
A good thing about this question is that even if you miss the 3 minutes late/early part i.e. if by mistake solve for 3 hours late/early, you will get the same Answer, I suppose.

Kudos [?]: 13 [0], given: 21

2 KUDOS received
Director
Director
avatar
Joined: 03 Aug 2012
Posts: 899

Kudos [?]: 931 [2], given: 322

Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GMAT 2: 680 Q50 V32
GPA: 3.7
WE: Information Technology (Investment Banking)
Premium Member
Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 24 Sep 2013, 22:29
2
This post received
KUDOS
2
This post was
BOOKMARKED
Home...........................................Workplace
40 m/h t+3
60 m/h t-3
x m/h t

We know that distance is constant hence

40(t+3) = 60 (t-3) = Distance

t=15
Distance =720

X = Distance/t

hence x=48
_________________

Rgds,
TGC!
_____________________________________________________________________
I Assisted You => KUDOS Please
_____________________________________________________________________________

Kudos [?]: 931 [2], given: 322

Intern
Intern
avatar
Joined: 15 May 2014
Posts: 27

Kudos [?]: 29 [0], given: 22

Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 26 Sep 2014, 03:54
3
This post was
BOOKMARKED
fozzzy wrote:
Mr Ben leaves his house for work at exactly 8:00 AM every morning. When he averages 40 miles per hour, he arrives at his workplace three minutes late. When he averages 60 miles per hour, he arrives three minutes early. At what average speed, in miles per hour, should Mr. Ben drive to arrive at his workplace precisely on time?

A) 45
B) 48
C) 50
D) 55
E) 58

[Reveal] Spoiler:
Here is what I did

\(\frac{D}{40} - \frac{3}{60} = \frac{D}{60} + \frac{3}{60}\)

Solve this equation to get

\(D = 12\)

\(\frac{D}{40} - \frac{3}{60}\) ( will this equation give me the time?)

we get \(\frac{1}{4}\)

R * T = D

\(\frac{1}{4} * X = 12\)

X = 48

Is this correct?


Can someone tell me is there is any problem if I try and solve it like this:

Let usual time taken = t
Distance = d

Time taken if he's 3 minutes late = t + 3
Time taken if he's 3 minutes early = t - 3

Distance, d = 40 x (t + 3) [when he's late]
Distance, d = 60 x (t - 3) [when he's early]

Hence, 40 x (t + 3) = 60 x (t - 3)
t = 15

if we plug the value of t in any of the equations:
d = 40 x (15 + 3) = 40 x 18 = 720

Average speed = Distance / Time = 720 / 15 = 48

Kudos [?]: 29 [0], given: 22

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42620

Kudos [?]: 135696 [0], given: 12706

Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 26 Sep 2014, 06:09
iaratul wrote:
fozzzy wrote:
Mr Ben leaves his house for work at exactly 8:00 AM every morning. When he averages 40 miles per hour, he arrives at his workplace three minutes late. When he averages 60 miles per hour, he arrives three minutes early. At what average speed, in miles per hour, should Mr. Ben drive to arrive at his workplace precisely on time?

A) 45
B) 48
C) 50
D) 55
E) 58

[Reveal] Spoiler:
Here is what I did

\(\frac{D}{40} - \frac{3}{60} = \frac{D}{60} + \frac{3}{60}\)

Solve this equation to get

\(D = 12\)

\(\frac{D}{40} - \frac{3}{60}\) ( will this equation give me the time?)

we get \(\frac{1}{4}\)

R * T = D

\(\frac{1}{4} * X = 12\)

X = 48

Is this correct?


Can someone tell me is there is any problem if I try and solve it like this:

Let usual time taken = t
Distance = d

Time taken if he's 3 minutes late = t + 3
Time taken if he's 3 minutes early = t - 3

Distance, d = 40 x (t + 3) [when he's late]
Distance, d = 60 x (t - 3) [when he's early]

Hence, 40 x (t + 3) = 60 x (t - 3)
t = 15

if we plug the value of t in any of the equations:
d = 40 x (15 + 3) = 40 x 18 = 720

Average speed = Distance / Time = 720 / 15 = 48


Yes, your approach is correct.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135696 [0], given: 12706

CR Forum Moderator
User avatar
P
Status: The best is yet to come.....
Joined: 10 Mar 2013
Posts: 503

Kudos [?]: 222 [0], given: 199

GMAT ToolKit User CAT Tests
Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo [#permalink]

Show Tags

New post 03 Dec 2017, 09:45
Bunuel wrote:
iaratul wrote:

Time taken if he's 3 minutes late = t + 3
Time taken if he's 3 minutes early = t - 3
Yes, your approach is correct.

Wouldn't t+3 be t+3/60?
_________________

Hasan Mahmud

Kudos [?]: 222 [0], given: 199

Re: Mr Ben leaves his house for work at exactly 8:00 AM every mo   [#permalink] 03 Dec 2017, 09:45
Display posts from previous: Sort by

Mr Ben leaves his house for work at exactly 8:00 AM every mo

  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®.