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

It is currently 21 Oct 2014, 11:21

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

What is the number of 360-degree rotations that a bicycle

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 18 Jun 2007
Posts: 88
Followers: 2

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

What is the number of 360-degree rotations that a bicycle [#permalink] New post 23 Aug 2007, 14:42
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

81% (01:36) correct 19% (00:39) wrong based on 124 sessions
What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?

(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.

OPEN DISCUSSION OF THIS QUESTION IS HERE: what-is-the-number-of-360-degree-rotations-that-a-bicycle-wh-166668.html
[Reveal] Spoiler: OA

Last edited by Bunuel on 21 May 2014, 00:55, edited 2 times in total.
Renamed the topic, edited the question and added OA.
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Manager
Manager
avatar
Status: Bell the GMAT!!!
Affiliations: Aidha
Joined: 16 Aug 2011
Posts: 186
Location: Singapore
Concentration: Finance, General Management
GMAT 1: 680 Q46 V37
GMAT 2: 620 Q49 V27
GMAT 3: 700 Q49 V36
WE: Other (Other)
Followers: 5

Kudos [?]: 39 [0], given: 43

Re: rate [#permalink] New post 29 Sep 2011, 02:53
Statement 2: You can not simply use unitary method here. We don't know how much distance the wheel covers in one rotation. For example, say wheel covers 10m in one rotation, so it will take 10 rotations to cover 100m where as if wheel covers 5m in one rotation, it will will take 20 rotations to cover the same distance. Also number of rotation here is not a function of time taken to complete the rotation.
Hope it helps.
_________________

If my post did a dance in your mind, send me the steps through kudos :)

My MBA journey at http://mbadilemma.wordpress.com/

Senior Manager
Senior Manager
User avatar
Joined: 03 Mar 2010
Posts: 446
Schools: Kelley,Tepper,Carlson,Kenan Flager,Broad
Followers: 4

Kudos [?]: 119 [0], given: 22

Re: rate [#permalink] New post 29 Sep 2011, 05:49
siddhans wrote:
20 X 60 (secs) = 1200 m travelled


How does number 20 multiplied by 60 seconds became 1200 meters ?
_________________

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

Manager
Manager
User avatar
Status: Target MBA
Joined: 20 Jul 2010
Posts: 212
Location: Singapore
Followers: 0

Kudos [?]: 9 [0], given: 12

Re: rate [#permalink] New post 01 Oct 2011, 01:08
siddhans wrote:
Searched but couldnt find... so posted


what is the number of 360 degree rotations that a bicycle wheel made while rotating 100 meters in a straight line without slipping?

1) The diameter of the bicycle wheel , including the tire, was 0.5 m

2) The wheel made twenty 360-degree rotations per min

[Reveal] Spoiler: My doubt
1) No of rotations = Total Distance/ Circumference = 100/2 * pi *r
1 --- Sufficient


2) 20 rotations in 60 secs

Rate X Time = Distance travelled

20 X 60 (secs) = 1200 m travelled


It travels 1200 m in 60 secs

1200 m ----- 60 secs
100 m -----??

cross - multiply

100 *60
--------- = 5 secs
1200


Rate * time = distance



Plug in distance =100 m

time = 5 secs

rate = 20

So ans should be D

but OA is A

What am i doing wrong here?


(1) n x pi x diameter = distance moved
distance moved = 100m
diameter = 0.5m
n = number of rotations

n = 100/(pi x 0.5)
Sufficient

(2) Not sufficient to get "n"

Answer should be A
_________________

Thanks and Regards,
GM.

Director
Director
avatar
Joined: 29 Nov 2012
Posts: 929
Followers: 12

Kudos [?]: 311 [0], given: 543

Re: What is the number of 360 degree rotations that a bicycle [#permalink] New post 06 Jan 2013, 03:55
How do you solve this one?
_________________

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 gmat-prep-software-analysis-and-what-if-scenarios-146146.html

Expert Post
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Preparing for the another shot...!
Joined: 03 Feb 2011
Posts: 1425
Location: India
Concentration: Finance, Marketing
GPA: 3.75
Followers: 129

Kudos [?]: 644 [0], given: 62

GMAT ToolKit User Premium Member
Re: What is the number of 360 degree rotations that a bicycle [#permalink] New post 06 Jan 2013, 04:24
Expert's post
fozzzy wrote:
How do you solve this one?


The distance is given. The question is asking the number of 360 degree rotations.
By 360 degree rotations, it means the number of revolutions.
The number of revolutions don't depend on the speed but just the radius.
The number of revolutions will be 1000/2*pi*R.

Statement 2 just gives the speed, but it doesn't gives the radius.
Hence +1A
_________________

Prepositional Phrases Clarified|Elimination of BEING| Absolute Phrases Clarified
Rules For Posting
www.Univ-Scholarships.com

Director
Director
avatar
Joined: 29 Nov 2012
Posts: 929
Followers: 12

Kudos [?]: 311 [0], given: 543

Re: What is the number of 360 degree rotations that a bicycle [#permalink] New post 07 Jan 2013, 05:37
Marcab wrote:
fozzzy wrote:
How do you solve this one?


The distance is given. The question is asking the number of 360 degree rotations.
By 360 degree rotations, it means the number of revolutions.
The number of revolutions don't depend on the speed but just the radius.
The number of revolutions will be 1000/2*pi*R.

Statement 2 just gives the speed, but it doesn't gives the radius.
Hence +1A


Is this the general formula to solve this type of problems so I can apply this to PS questions
_________________

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 gmat-prep-software-analysis-and-what-if-scenarios-146146.html

Expert Post
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Preparing for the another shot...!
Joined: 03 Feb 2011
Posts: 1425
Location: India
Concentration: Finance, Marketing
GPA: 3.75
Followers: 129

Kudos [?]: 644 [0], given: 62

GMAT ToolKit User Premium Member
Re: What is the number of 360-degree rotations that a bicycle [#permalink] New post 07 Jan 2013, 05:41
Expert's post
No its not a formula. Its simple logic.
Circumfrence is the total distance that a wheel will cover in one rotation. Since the distance is 1000m, therefore the number of revolutions will be 1000/circumfrence.
Hope its clear.
_________________

Prepositional Phrases Clarified|Elimination of BEING| Absolute Phrases Clarified
Rules For Posting
www.Univ-Scholarships.com

Intern
Intern
avatar
Joined: 25 Apr 2013
Posts: 26
Location: India
GMAT 1: 670 Q48 V34
GMAT 2: 720 Q50 V38
GRE 1: 320 Q163 V157
WE: General Management (Non-Profit and Government)
Followers: 0

Kudos [?]: 7 [0], given: 12

Re: rate [#permalink] New post 14 Nov 2013, 07:13
Let me put it this way
Distance (m) = Speed (m/s) * Time (s) => (m/s)*s = metres
In the explanation that you had put forward, you had used "no of rotations" in place of speed. No of rotations is basically a number. It does not translate into speed.
Senior Manager
Senior Manager
avatar
Joined: 19 Oct 2010
Posts: 274
Location: India
GMAT 1: 560 Q36 V31
GPA: 3
Followers: 6

Kudos [?]: 37 [0], given: 27

Re: What is the number of 360-degree rotations that a bicycle [#permalink] New post 21 May 2014, 00:16
Sumithra Sen wrote:
What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?

(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.



I see how this must be A. But how can you consider the tire to be of negligible thickness when it does not say so in statement 1? Moreover the question does not say anything about the tire. Don't you need to consider its thickness? In which case, it will be E.

Can someone explain this?
_________________

petrifiedbutstanding

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23355
Followers: 3604

Kudos [?]: 28717 [0], given: 2821

Re: What is the number of 360-degree rotations that a bicycle [#permalink] New post 21 May 2014, 00:59
Expert's post
petrifiedbutstanding wrote:
Sumithra Sen wrote:
What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?

(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.



I see how this must be A. But how can you consider the tire to be of negligible thickness when it does not say so in statement 1? Moreover the question does not say anything about the tire. Don't you need to consider its thickness? In which case, it will be E.

Can someone explain this?


(1) says that "the diameter of the bicycle wheel, including the tire, was 0.5 meter". So, we have the diameter of the whole wheel, we don't need the the thickness of tire.

What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?

1 revolution of a circle = circumference of that circle. So, we basically asked to find the value of 100/(circumference).

(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter. We can get the circumference. Sufficient.

(2) The wheel made twenty 360-degree rotations per minute. We cannot get the circumference. Not sufficient.

Answer: A.

Similar questions to practice:
a-circular-rim-28-inches-in-diameter-rotates-the-same-number-65106.html
two-wheels-are-connected-via-a-conveyor-belt-the-larger-133697.html
how-long-in-minutes-did-it-take-a-bicycle-wheel-to-roll-130026.html

OPEN DISCUSSION OF THIS QUESTION IS HERE: what-is-the-number-of-360-degree-rotations-that-a-bicycle-wh-166668.html
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4877
Location: Pune, India
Followers: 1152

Kudos [?]: 5350 [0], given: 165

Re: What is the number of 360-degree rotations that a bicycle [#permalink] New post 21 May 2014, 01:12
Expert's post
petrifiedbutstanding wrote:
Sumithra Sen wrote:
What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?

(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.



I see how this must be A. But how can you consider the tire to be of negligible thickness when it does not say so in statement 1? Moreover the question does not say anything about the tire. Don't you need to consider its thickness? In which case, it will be E.

Can someone explain this?


Responding to a pm:

Whatever is the number of rotations made by the outside surface of the wheel, the same will be the number of rotations made by the entire wheel. Imagine inserting a long needle from the tire reaching up to the center of the wheel. Every point in the needle will complete one circle at the same time.

Also, the stmnt tells you that the diameter of the wheel including the tire is 0.5 to clarify properly. Else, in common parlance, wheel pretty much includes the tire as well.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Re: What is the number of 360-degree rotations that a bicycle   [#permalink] 21 May 2014, 01:12
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic What is the number of 360-degree rotations that a bicycle wh Bunuel 5 26 Jan 2014, 09:44
A circular rim 28 inches in diameter rotates the same number gmat2006-8001 9 09 Dec 2007, 10:21
9 Experts publish their posts in the topic A circular rim 28 inches in diameter rotates the same number acoustic 6 08 Nov 2006, 15:15
A circular rim 28 inches in diameter rotates the same number uvs_mba 4 07 Nov 2006, 07:29
A circular rim 28 inches in diameter rotates the same number Matador 2 15 Apr 2006, 19:59
Display posts from previous: Sort by

What is the number of 360-degree rotations that a bicycle

  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®.