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

 It is currently 01 Sep 2015, 14:38

### 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

# Timothy leaves home for school, riding his bicycle

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Moderator
Joined: 01 Sep 2010
Posts: 2653
Followers: 511

Kudos [?]: 3949 [0], given: 727

Timothy leaves home for school, riding his bicycle [#permalink]  02 Sep 2012, 14:59
Expert's post
5
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

72% (03:01) correct 28% (02:04) wrong based on 157 sessions
Timothy leaves home for school, riding his bicycle at a rate of 9 miles per hour. Fifteen minutes after he leaves, his mother sees Timothy’s math homework lying on his bed and immediately leaves home to bring it to him. If his mother drives at 36 miles per hour, how far (in terms of miles) must she drive before she reaches Timothy?

A) 1/3
B) 3
C) 4
D) 9
E) 12

I think is a 700 level problem but I tag it as 600/700, let me know. Either way I hope in an explanation Thanks
[Reveal] Spoiler: OA

_________________
Status: Tutor
Joined: 05 Apr 2011
Posts: 536
Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 570 Q49 V19
GMAT 2: 700 Q51 V31
GPA: 3
WE: Information Technology (Computer Software)
Followers: 72

Kudos [?]: 388 [1] , given: 47

Re: Timothy leaves home for school, riding his bicycle [#permalink]  02 Sep 2012, 19:41
1
KUDOS
1
This post was
BOOKMARKED
Timothy leaves home for school, riding his bicycle at a rate of 9 miles per hour. Fifteen
minutes after he leaves, his mother sees Timothy’s math homework lying on his bed and
immediately leaves home to bring it to him. If his mother drives at 36 miles per hour, how far
(in terms of miles) must she drive before she reaches Timothy?

A) 1/3

B) 3

C) 4

D) 9

E) 12

Suppose Timothy's mom meets him after time 't'

Then distance traveled by his mom = distance traveled by him in (15mins) + distance traveled by him in time 't'

=> 36 * t = 9 *(15/60) + 9*t
=> t = (1/12) hrs

Distance traveled = 36 * t = 36 * (1/12) miles = 3miles

So, Answer will be B

And am not sure about the tag but i guess 600-700 is fine.

Hope it helps!
_________________
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 5863
Location: Pune, India
Followers: 1481

Kudos [?]: 7972 [1] , given: 190

Re: Timothy leaves home for school, riding his bicycle [#permalink]  10 May 2015, 21:29
1
KUDOS
Expert's post
carcass wrote:
Timothy leaves home for school, riding his bicycle at a rate of 9 miles per hour. Fifteen minutes after he leaves, his mother sees Timothy’s math homework lying on his bed and immediately leaves home to bring it to him. If his mother drives at 36 miles per hour, how far (in terms of miles) must she drive before she reaches Timothy?

A) 1/3
B) 3
C) 4
D) 9
E) 12

I think is a 700 level problem but I tag it as 600/700, let me know. Either way I hope in an explanation Thanks

This is a simple relative speed question. Here is a conceptual post on relative speed: http://www.veritasprep.com/blog/2012/07 ... elatively/

Distance Timothy covers in 15 mins i.e. 1/4 hours = Rate*Time = 9/4 miles
Time taken by mom to meet him = Distance/Relative Speed = (9/4)/(36 - 9) = 1/12 hours
Distance traveled by mom in this time = 36 * (1/12) = 3 miles
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 6162
Followers: 344

Kudos [?]: 70 [0], given: 0

Re: Timothy leaves home for school, riding his bicycle [#permalink]  23 Aug 2014, 19:51
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Senior Manager
Joined: 23 Jan 2013
Posts: 377
Schools: Cambridge'16
Followers: 2

Kudos [?]: 33 [0], given: 33

Re: Timothy leaves home for school, riding his bicycle [#permalink]  10 May 2015, 02:58
9*1/4=9/4 miles Timothy ran before his mom started

36-9=27m/h is a rate to achieve Timothy

9/4:27=1/12 h is a time mom will run

36*1/12=3 miles mom need to run

B
EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 3478
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Followers: 148

Kudos [?]: 932 [0], given: 57

Re: Timothy leaves home for school, riding his bicycle [#permalink]  10 May 2015, 15:32
Expert's post
Hi All,

Sometimes these types of Combined Rate/Chase-Down questions can be really complicated, but this one is not so bad. You can actually solve it with some logic and a little bit of math (and avoid the longer calculation-heavy approach).

Based on what we're told in the prompt, we know that Timothy travels on his own at 9mph for 15 minutes. Since 15 minutes = 1/4 of an hour, Timothy traveled 2.25 miles before his Mom gets in the car to chase him down.

Since the Mom drives 36mph and Timothy is only going 9mph, she is traveling 4 TIMES FASTER than he is. In basic terms, this means that for every 1 mile Timothy travels, his Mom travels 4 miles.

So, if Timothy DID travel another 1 mile, he'd have traveled 2.25 + 1 = 3.25 miles while his Mom would have driven 4 miles (and gone past him). This means that his Mom caught him at some point between 2.25 miles and 3.25 miles. There's only one answer that 'fits'....

[Reveal] Spoiler:
B

GMAT assassins aren't born, they're made,
Rich
_________________

e-GMAT Representative
Joined: 04 Jan 2015
Posts: 338
Followers: 65

Kudos [?]: 479 [0], given: 83

Re: Timothy leaves home for school, riding his bicycle [#permalink]  11 May 2015, 01:42
Expert's post
In Time, Speed and Distance problems, it's a good idea to draw a rough diagram to visualize the given information.

Let the distance between the Home and the Point of Meeting be D miles. The question asks us to find the value of D.

As per the question, Timothy's mother left home 15 minutes after he did. But they both reached the Point of Meeting at the same time.

This means,

(Time taken by Timothy's mother to cover D miles) = (Time taken by Timothy to cover D miles) - (15 minutes)

Now, $$Time = \frac{Distance}{Speed}$$

So, the above equation becomes:

$$\frac{D}{36} = \frac{D}{9} - \frac{15}{60}$$

Upon solving this, we get, D = 3 miles

One important point to be careful of in Distance and Speed questions is: Use the same units for a particular quantity throughout the question. By this I mean, if the speed is expressed in miles per hour and travel time/ difference between time taken by 2 people is given in minutes, then you must remember to either convert the time from minutes to hours or convert the speed from miles per hours to miles per minutes. Throughout the question, you should use only one unit for time.

Hope this helped!

Japinder
_________________
Re: Timothy leaves home for school, riding his bicycle   [#permalink] 11 May 2015, 01:42
Similar topics Replies Last post
Similar
Topics:
6 Mike and Lidia are 106 miles apart and will begin riding their bicycle 8 17 Jul 2015, 00:13
7 Anwar leaves home everyday at 4 p.m to pick his son from 5 15 Jul 2013, 07:59
3 Before leaving home for the town of Madison, Pete checks a 6 17 Sep 2010, 02:24
Norman and his bicycles 4 05 Jul 2009, 13:42
6 A cyclist rides his bicycle over a route which is 1/3 uphill 17 21 Mar 2007, 17:20
Display posts from previous: Sort by

# Timothy leaves home for school, riding his bicycle

 Question banks Downloads My Bookmarks Reviews Important topics

 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®.