GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 08 Dec 2019, 13:32

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

A point on the edge of a fan blade that is rotating in a plane is 10

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
Joined: 23 Mar 2008
Posts: 196
A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post Updated on: 14 Apr 2015, 04:16
23
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

78% (01:44) correct 22% (02:06) wrong based on 493 sessions

HideShow timer Statistics

A point on the edge of a fan blade that is rotating in a plane is 10 centimeters from the center of the fan. WHat is the distance traveled, in centimeters, by this point in 15 seconds when the fan runs at the rate of 300 revolutions per minutes?

A. 750pi
B. 1500pi
C. 1875pi
D. 3000pi
E. 7500pi

Originally posted by puma on 15 Jun 2008, 10:28.
Last edited by Bunuel on 14 Apr 2015, 04:16, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
Intern
Intern
avatar
Joined: 13 Jun 2008
Posts: 4
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 15 Jun 2008, 10:36
1
2
300/(60/15) = 75 revolutions
1 revolution = 2*pi*r = 20pi
20pi*75=1500pi

puma wrote:
A point on the edge of a fan blade that is rotating in a plane is 10 centimeters from the center of the fan. WHat is the distance traveled, in centimeters, by this point in 15 seconds when the fan runs at the rate of 300 revolutions per minutes?

A) 750pi
B) 1500pi
C) 1875pi
D) 3000pi
E) 7500pi
Manager
Manager
avatar
Joined: 14 Feb 2011
Posts: 143
Re: PS word problem  [#permalink]

Show Tags

New post 08 May 2011, 10:59
2
1
carollu wrote:
A point on the edge of a fan blade that is rotating in a plane is 10 centimetres from the centre of the fan. What is the distance traveled, in cms, by this point in 15 seconds when the fan runs at the rate of 300 revolutions per minute?

a)750 pie
b)1500 pie
c)1875 pie
d)3000 pie
e)7500 pie


Distance traveled in one revolution is \(2*\pi*r = 2*\pi*10 = 20\pi\)

Number of revolutions in 15 seconds when fan runs at the rate of 300 revolutions per minute = \(300*15/60 = 75\)

So total distance traveled = \(75*20\pi = 1500*\pi\) Answer B
Intern
Intern
avatar
Joined: 29 Mar 2011
Posts: 16
Re: PS word problem  [#permalink]

Show Tags

New post 08 May 2011, 12:32
RAdius of the circular plane in which point travels is 10 cms
in one revolution = 20pie
in 15 seconds fan makes 75 revs (300*15/60)
So total distance = 75*20pie
1500 pie
Director
Director
avatar
Joined: 01 Feb 2011
Posts: 531
Re: PS word problem  [#permalink]

Show Tags

New post 08 May 2011, 20:14
1
given data

60 seconds - 300 revolutions
15 seconds - 75 revolutions


distance travelled in 1 revolution = 2*pi*r
distance travelled in 75 revolutions = 150*pi*r
= 1500pi

Answer is B.
Director
Director
avatar
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 821
Re: PS word problem  [#permalink]

Show Tags

New post 08 May 2011, 20:40
Revolutions /sec = 300/60 = 5
In 15 sec, revolutions = 15*5 = 75

distance traveled/ revolution = circumference = 2 * pi * (10)

Thus total distance in 15 sec = 2 * pi * (10) * 75

1800 * pi
EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 15669
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 13 Apr 2015, 18:19
Hi All,

While this is an old post, it's a decent example of how the GMAT can test you on Geometry concepts using real-world items (and a story problem).

We're told that a fan blade is 10cm from the center of the fan (which means we have a radius of 10). We're then told that the fan blade spins for 15 seconds (which means that we're dealing with the circumference of a circle). We're asked how far the point "travels" if the fan makes 300 revolutions per minute.

The 'math' involved in this question can be done in a couple of different ways, but here's a step-by-step method that should be easy to follow:

Since radius = 10
Circumference = 2(pi)(R) = 2(pi)(10) = 20pi

So every revolution = 20pi cm traveled

15 seconds = 1/4 of a minute
(300 revolutions/minute)(1/4 of a minute) = 75 revolutions in 15 seconds

(20pi cm)(75) = 1500pi cm

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________
Contact Rich at: Rich.C@empowergmat.com
Image


The Course Used By GMAT Club Moderators To Earn 750+

souvik101990 Score: 760 Q50 V42 ★★★★★
ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 59590
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 14 Apr 2015, 04:19
1
1
puma wrote:
A point on the edge of a fan blade that is rotating in a plane is 10 centimeters from the center of the fan. WHat is the distance traveled, in centimeters, by this point in 15 seconds when the fan runs at the rate of 300 revolutions per minutes?

A. 750pi
B. 1500pi
C. 1875pi
D. 3000pi
E. 7500pi


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
what-is-the-number-of-360-degree-rotations-that-a-bicycle-wh-166668.html
the-circumference-of-the-front-wheel-of-a-cart-is-30-ft-long-90588.html
m10-183873.html

Hope it helps.
_________________
Intern
Intern
avatar
B
Joined: 12 Jul 2016
Posts: 17
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 25 May 2017, 03:59
1
Hi,
what would be the level of this question ?
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 59590
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 25 May 2017, 04:28
Manager
Manager
User avatar
G
Joined: 22 Nov 2016
Posts: 205
Location: United States (CA)
Concentration: Leadership, Strategy
Schools: Haas EWMBA '22
GMAT 1: 640 Q43 V35
GPA: 3.4
Reviews Badge
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 06 Jul 2017, 17:35
When given the speed in revolutions, the distance traveled will be speed * circumference
Here, the distance in 60 seconds = \(300 * 2*\pi*10\)
Hence the distance traveled in 15 seconds = \(\frac{15}{60}\) * \(300 * 2*\pi*10\) = \(1500\pi\)

Answer is B
Target Test Prep Representative
User avatar
V
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8622
Location: United States (CA)
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 10 May 2018, 10:41
puma wrote:
A point on the edge of a fan blade that is rotating in a plane is 10 centimeters from the center of the fan. WHat is the distance traveled, in centimeters, by this point in 15 seconds when the fan runs at the rate of 300 revolutions per minutes?

A. 750pi
B. 1500pi
C. 1875pi
D. 3000pi
E. 7500pi


One entire revolution is equal to the circumference of the circle, which is 2 x π x 10 = 20π.

We must convert 300 revolutions per minute to revolutions per second: 300/60 = 5 revolutions per second. So in 15 seconds the number of revolutions is 5 x 15 = 75 revolutions.

So the total distance traveled is 20π x 75 = 1500π.

Answer: B
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Intern
Intern
User avatar
B
Joined: 21 Aug 2018
Posts: 21
Location: France
Schools: Erasmus '20
GMAT 1: 390 Q22 V23
GPA: 2.8
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 07 Sep 2019, 02:40
As usual from me, an alternative reasoning, however it can prove very useful and quick when needed:

You can imagine the fan blades inside the fan in your head, which basically comes back to draw a circle with the edge being a point at the edge of the circle!

2nd step: You can now deduct from the given info that the radius (distance from the edge of circle to the center of the circle) is of 10cm, with the perimeter being 2d=20cm!

3rd step: You can deduct that revolution=complete travel of the circle's area by the fan blade, at the rhythm of 300r/minute. You can also deduct that 15 seconds is 1/4 of a minute!

4th step: We combine all the info given and deducted to arrive at 300revolution x 20cm (diameter)=6000revolutions/minute, but we're only interested in 15 seconds, or 1/4 of a minute so 1/4th of 6000, which is equal to...1500!

The complete calculus is: 300 x 20=6000/4=1500 :)

Answer B for the win! :) Hope this was useful!
Intern
Intern
User avatar
B
Joined: 13 Aug 2018
Posts: 12
Location: India
Concentration: Marketing, International Business
WE: Information Technology (Internet and New Media)
CAT Tests
Re: A point on the edge of a fan blade that is rotating in a plane is 10  [#permalink]

Show Tags

New post 07 Sep 2019, 03:01
1
A point on the edge of a fan blade that is rotating in a plane is 10 centimeters from the center of the fan. WHat is the distance traveled, in centimeters, by this point in 15 seconds when the fan runs at the rate of 300 revolutions per minutes?

A point on the edge of a fan blade that is rotating in a plane denoted the radius of the fan = 10 cm
1 resolution = 1 complete circumference of the circle/fan
300 resolutions per min = 300/60= 5 res/sec
in 15 sec, total res = 5X15= 75
Distance covered in 15 secs= 75 X 2 X pi X 10 = 1500 pi
GMAT Club Bot
Re: A point on the edge of a fan blade that is rotating in a plane is 10   [#permalink] 07 Sep 2019, 03:01
Display posts from previous: Sort by

A point on the edge of a fan blade that is rotating in a plane is 10

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne