It is currently 21 Oct 2017, 00:21

### 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

# Cylinder A, which has a radius of x and a height of y, has a greater

Author Message
TAGS:

### Hide Tags

Manager
Joined: 24 Jul 2011
Posts: 229

Kudos [?]: 48 [0], given: 93

Location: India
GMAT 1: 570 Q50 V19
GMAT 2: 650 Q49 V28
GMAT 3: 690 Q50 V34
WE: Information Technology (Investment Banking)
Cylinder A, which has a radius of x and a height of y, has a greater [#permalink]

### Show Tags

30 Sep 2015, 23:40
00:00

Difficulty:

(N/A)

Question Stats:

50% (02:06) correct 50% (01:26) wrong based on 16 sessions

### HideShow timer Statistics

Geometry MGMAT Question Bank Q24

Cylinder A, which has a radius of x and a height of y, has a greater surface area than does Cylinder B, which has a radius of y and a height of x. How much greater is the surface area of Cylinder A than that of Cylinder of B?

Though options are not available, still it's a good questions.
[Reveal] Spoiler: A
x/y

_________________

Middle of nowhere!

Last edited by Bunuel on 01 Oct 2015, 00:56, edited 1 time in total.
RENAMED THE TOPIC.

Kudos [?]: 48 [0], given: 93

Math Forum Moderator
Joined: 02 Aug 2009
Posts: 4985

Kudos [?]: 5496 [0], given: 112

Re: Cylinder A, which has a radius of x and a height of y, has a greater [#permalink]

### Show Tags

01 Oct 2015, 19:39
rohitmanglik wrote:
Geometry MGMAT Question Bank Q24

Cylinder A, which has a radius of x and a height of y, has a greater surface area than does Cylinder B, which has a radius of y and a height of x. How much greater is the surface area of Cylinder A than that of Cylinder of B?

Though options are not available, still it's a good questions.
[Reveal] Spoiler: A
x/y

Hi,
1. Q-- what is the ratio of surface area of cylinder A to cylinder B?..... Ans$$\frac{x}{y}$$
2. for your Q, the answer will $$2pi(x^2-y^2)$$...... How can you have an answer without 2 pi, when both the quantity have 2pi in it...
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

Kudos [?]: 5496 [0], given: 112

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 4142

Kudos [?]: 2898 [0], given: 0

GPA: 3.82
Re: Cylinder A, which has a radius of x and a height of y, has a greater [#permalink]

### Show Tags

01 Oct 2015, 22:55
Expert's post
1
This post was
BOOKMARKED
Forget conventional ways of solving math questions. In PS, IVY approach is the easiest and quickest way to find the answer.

Cylinder A, which has a radius of x and a height of y, has a greater surface area than does Cylinder B, which has a radius of y and a height of x. How much greater is the surface area of Cylinder A than that of Cylinder of B?

Hi! Well your question is a little bit ambiguous... However, as you mentioned, it is a good question.
So let’s try to get areas of Cylinder A and B.
First of all a Cylinder has two circles(bottom and top) and a rectangle(side) so the area of Cylinder A is 2*pi*x^2 + 2*pi*x*y.
Similarly the area of Cynlinder B is 2*pi*y^2 + 2*pi*x*y.

Since Cylinder A has a greater surface area than does Cylinder B, x > y.
So the difference of area is 2*pi*x^2 + 2*pi*x*y -(2*pi*y^2 + 2*pi*x*y) = 2*pi(x^2 –y^2)
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself

Kudos [?]: 2898 [0], given: 0

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16610

Kudos [?]: 273 [0], given: 0

Re: Cylinder A, which has a radius of x and a height of y, has a greater [#permalink]

### Show Tags

03 Sep 2017, 00:54
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.
_________________

Kudos [?]: 273 [0], given: 0

Re: Cylinder A, which has a radius of x and a height of y, has a greater   [#permalink] 03 Sep 2017, 00:54
Display posts from previous: Sort by