NEW HERE? LEARN MORE
closeclose
It is currently 16 Apr 2024, 12:12
Register
GMAT Focus Tests
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

A wheel has a diameter of x inches and a second wheel has a diameter

10 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Question banks

GMAT Question Banks

Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92698
CAT Tests Forum Quiz Mode
A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  20 Jan 2015, 06:34
15
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

25% (medium)

Question Stats:

76% (01:54) correct 24% (01:55) wrong based on 240 sessions
Hide Show timer Statistics
A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y

Kudos for a correct solution.
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.

_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
Most Helpful Reply
avatar
B
chandan276
Intern
Intern
Joined: 05 Dec 2014
Posts: 3
Concentration: Finance, Technology
GMAT Date: 04-25-2015
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  20 Jan 2015, 21:05
6
Kudos
3
Bookmarks
[quote="Bunuel"]A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y


First Wheel with diameter x inches ----> So the circumference = x*pi --------- (1)
Second Wheel with diameter y inches ----> So the circumference = y*pi --------- (2)

Now,
Revolutions = distance/circumference

So, from equation (1)
100 = d/(x*pi)
d = 100 * x * pi ---------- (3)

From equation (2)
Revolutions = d/(y*pi) = (100 * x * pi) / (y*pi) = 100x/y

Answer (E)
General Discussion
avatar
B
82vkgmat
Manager
Manager
Joined: 02 Sep 2014
Posts: 70
Location: United States
Schools: Haas EWMBA '20 (A)
GMAT 1: 770 Q50 V44
GPA: 3.97
GMAT ToolKit User Reviews Badge
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  20 Jan 2015, 23:41
1
Kudos
d feet = 12d inches = 100 revolutions = 100*circumference = 100*(pi)*x
For same distance # revolutions for second wheel = distance/circumference = 100*pi*x/(pi*y) = 100x/y.

Answer E.


Bunuel wrote:
A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y

Kudos for a correct solution.
avatar
PareshGmat
SVP
SVP
Joined: 27 Dec 2012
Status:The Best Or Nothing
Posts: 1563
Location: India
Concentration: General Management, Technology
WE:Information Technology (Computer Software)
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  22 Jan 2015, 21:48
1
Kudos
1
Bookmarks
Answer = E. 100x/y


............................ Wheel A ..................... Wheel B

Diameter .................. x .............................. y

Radius .................... \(\frac{x}{2}\) ............................ \(\frac{y}{2}\)

Circumference .......... \(\frac{d}{100}\) ......................... \(2\pi(\frac{y}{2})\) .............

\(2\pi(\frac{x}{2}) = \frac{d}{100}\)

\(d = 100\pi x\)

Revolutions of Wheel B to achieve distance d\(= \frac{100\pi x}{2\pi(\frac{y}{2})} = 100\frac{x}{y}\)
User avatar
KarishmaParmar
Manager
Manager
Joined: 15 Feb 2016
Posts: 52
GMAT 1: 710 Q48 V40
Reviews Badge
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  15 Feb 2016, 09:57
2
Kudos
Bunuel wrote:
A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y

Kudos for a correct solution.


A very simple Question

Circumference of a circle = pi * D = distance covered in one revolution.
For first circle, one revolution = pi*x
In 100 revolutions, distance covered = 100* pi*x = d feet
Second wheel in one revolution = pi*y
For d feet or for 100*pi*x it will take 100*pi*x / pi*y

or, 100x/y
Answer E

My Kudos Please :oops:
User avatar
L
Abhishek009
Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 6075
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
GMAT ToolKit User
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  14 May 2016, 08:00
Bunuel wrote:
A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y


Quote:
A wheel has a diameter of x inches..... covers a distance of d feet in 100 revolutions.


So, \(d\) = \(100*2π*\frac{x}{4}\)

Quote:
A second wheel has a diameter of y inches....How many revolutions does the second wheel make in covering d feet..


Circumference of the second wheel is \(2π*\frac{y}{4}\)

Quote:
How many revolutions does the second wheel make


=> \((100*2π*x/4) / (2π*y/4)\)

=> \(\frac{100x}{y}\)

Hence answer will be (E) \(\frac{100x}{y}\)
_________________
Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )
Signature Read More
User avatar
babuvgmat
Intern
Intern
Joined: 10 Dec 2014
Posts: 34
Location: India
Concentration: Entrepreneurship, Operations
Schools: ISB '17
GPA: 4
WE:Operations (Consulting)
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  15 May 2016, 00:34
A wheel covers 2πr distance in one revolution. where r= diameter/2

First wheel covers d feet in 100 rev. => d= 100* 2π * (x/2)

Second wheel covers d feet in let's say P revolutions; => d = P* 2π * (y/2)

comparing both equations:-

=> p= (100∗2π∗x/2)/(2π∗y/2)

=> 100x/y

OA :- E
User avatar
P
JeffTargetTestPrep
Target Test Prep Representative
Joined: 04 Mar 2011
Status:Head GMAT Instructor
Affiliations: Target Test Prep
Posts: 3043
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  12 Mar 2018, 16:26
Expert Reply
Bunuel wrote:
A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y


Recall that d feet = 12d inches and the circumference (C = 2πr or Dπ) of the x-inch diameter wheel = xπ and that of the y-inch diameter wheel = yπ.

Therefore, we know that in 1 revolution, the first wheel covers a distance of xπ inches. Thus, in 100 revolutions, it covers 12d inches, as shown here:
xπ * 100 = 12d

If we let r = the number of revolutions the second wheel makes, we have:

yπ * r = 12d

Thus, we have:

xπ * 100 = yπ * r

100x = yr

100x/y = r

Answer: E
_________________
See why Target Test Prep is the top rated GMAT course on GMAT Club. Read Our Reviews
Signature Read More
User avatar
L
KarishmaB
Tutor
Joined: 16 Oct 2010
Posts: 14804
Location: Pune, India
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  20 Jan 2021, 01:36
1
Kudos
Expert Reply
Bunuel wrote:
A wheel has a diameter of x inches and a second wheel has a diameter of y inches. The first wheel covers a distance of d feet in 100 revolutions. How many revolutions does the second wheel make in covering d feet?

A. 100xy
B. 100y - x
C. 100x - y
D. 100y/x
E. 100x/y

Kudos for a correct solution.


Distance travelled is the same in both cases.

Distance = Circumference of wheel * No of revolutions \(= 2*\pi*x/2 * 100 = 2*\pi*y/2 * R\)
R = 100x/y

Answer (E)

Note that we don't need to worry about different units because they will all cancel off anyway.
_________________
Karishma Bansal - ANA PREP

*SUPER SUNDAYS!* - FREE Access to ALL Resources EVERY Sunday
REGISTER at ANA PREP
(Includes access to Study Modules, Concept Videos, Practice Questions and LIVE Classes)

YouTube Channel
youtube.com/karishma.anaprep
Signature Read More
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32503
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink] New post  11 Nov 2023, 13:58
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.
_________________
GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources
Signature Read More
GMAT Club Bot
gmatclubot
Re: A wheel has a diameter of x inches and a second wheel has a diameter [#permalink]
11 Nov 2023, 13:58
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
Bunuel
Math Expert
92698 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

cron

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions