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

It is currently 26 Sep 2018, 03:55

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

If the ratio of the volumes of two right circular cylinders is given

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49496
If the ratio of the volumes of two right circular cylinders is given  [#permalink]

Show Tags

New post 07 Jul 2017, 01:55
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

89% (00:51) correct 11% (01:48) wrong based on 135 sessions

HideShow timer Statistics

If the ratio of the volumes of two right circular cylinders is given by 64/9, what is the ratio of their radii? (Both the cylinders have the same height)

(A) 4/3
(B) 8/3
(C) 16/9
(D) 4/1
(E) 16/3

_________________

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

Senior Manager
Senior Manager
avatar
P
Joined: 14 Oct 2015
Posts: 250
GPA: 3.57
Reviews Badge
If the ratio of the volumes of two right circular cylinders is given  [#permalink]

Show Tags

New post 07 Jul 2017, 02:48
1
Bunuel wrote:
If the ratio of the volumes of two right circular cylinders is given by 64/9, what is the ratio of their radii? (Both the cylinders have the same height)

(A) 4/3
(B) 8/3
(C) 16/9
(D) 4/1
(E) 16/3


It should be B.

Lets say larger of the two cylinders has radius R and height H. Smaller has the radius r and height h. We know that volume of cylinder is \(πR^2h\)

\(πR^2H / πr^2h\) = \(64/9\)

Since height is same, we can cross π and h

\(R^2/r^2\) = \(64/9\)

Taking square root of both sides and it comes out to be ratio of radii. 8/3 or B
_________________

Please hit Kudos if this post helped you inch closer to your GMAT goal.
Procrastination is the termite constantly trying to eat your GMAT tree from the inside.
There is one fix to every problem, working harder!

Director
Director
User avatar
D
Joined: 04 Dec 2015
Posts: 701
Location: India
Concentration: Technology, Strategy
Schools: ISB '19, IIMA , IIMB, XLRI
WE: Information Technology (Consulting)
GMAT ToolKit User
If the ratio of the volumes of two right circular cylinders is given  [#permalink]

Show Tags

New post 07 Jul 2017, 06:46
Bunuel wrote:
If the ratio of the volumes of two right circular cylinders is given by 64/9, what is the ratio of their radii? (Both the cylinders have the same height)

(A) 4/3
(B) 8/3
(C) 16/9
(D) 4/1
(E) 16/3


Let Volume of one cylinder be \(=\) \(\pi\)\(R^2h\)

Let Volume of second cylinder be \(=\) \(\pi\)\(r^2h\)

Given Both cylinders have same height.

Ratio of Volumes \(=> \frac{\pi(R^2)h}{\pi(r^2)h} = \frac{64}{9}\)

\(\frac{R^2}{r^2} = \frac{64}{9}\)

\(\sqrt{\frac{R^2}{r^2}} = \sqrt{\frac{64}{9}}\)

Ratio of Radii \(=> \frac{R}{r} = \frac{8}{3}\)

Answer (B)...
Manager
Manager
avatar
B
Joined: 23 Oct 2017
Posts: 64
Re: If the ratio of the volumes of two right circular cylinders is given  [#permalink]

Show Tags

New post 05 Jan 2018, 20:54
Volume of right circular cylinder V = pi*r^2*l
V1 = pi*r1^2*l1
V2 = pi*r2^2*l2

Ratio of volume: V1/V2 =64/9

Since l= is constant => l1=l2
V1/V2 =r1*r1/r2*r2 = 64/9
=> r1/r2 =8 /3
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2835
Re: If the ratio of the volumes of two right circular cylinders is given  [#permalink]

Show Tags

New post 26 Jul 2018, 16:34
Bunuel wrote:
If the ratio of the volumes of two right circular cylinders is given by 64/9, what is the ratio of their radii? (Both the cylinders have the same height)

(A) 4/3
(B) 8/3
(C) 16/9
(D) 4/1
(E) 16/3


Let the larger radius = R and the smaller radius = r; thus, we have:

(π R^2 h)/(π r^2 h) = 64/9

R^2/r^2 = 64/9

Taking the square root of both sides, we have:

R/r = 8/3

Answer: B
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

GMAT Club Bot
Re: If the ratio of the volumes of two right circular cylinders is given &nbs [#permalink] 26 Jul 2018, 16:34
Display posts from previous: Sort by

If the ratio of the volumes of two right circular cylinders is given

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

Events & Promotions

PREV
NEXT


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.