Last visit was: 18 Nov 2024, 14:43 It is currently 18 Nov 2024, 14:43

Close

GRE Prep 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 GRE 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
Verbal Expert
Joined: 18 Apr 2015
Posts: 29976
Own Kudos [?]: 36273 [0]
Given Kudos: 25915
Send PM
avatar
Manager
Manager
Joined: 18 Jun 2019
Posts: 122
Own Kudos [?]: 42 [0]
Given Kudos: 0
Send PM
avatar
Intern
Intern
Joined: 14 Sep 2019
Posts: 49
Own Kudos [?]: 22 [3]
Given Kudos: 0
Send PM
avatar
Intern
Intern
Joined: 17 Sep 2019
Posts: 4
Own Kudos [?]: 2 [0]
Given Kudos: 0
Send PM
Re: a and b are positive integers such that 4 < a + b < 6 and [#permalink]
kloppismydad wrote:
1st equation:

a+b = 5 (1)

2nd equation:

|a-b| = 1

a-b = 1 (2)
a-b = -1 (3)

Solving (1) and (2) gives us,
a = 3, b = 2

Solving (2) and (3) gives us,
a = 2, b = 3

Hence, volume of cylinder 1 = πr^2h = π*(3)^2*2 = 18π

Volume of cylinder 2 = π*(2)^2*3 = 12π

However, since radius a has two volumes, the answer is D.


Thank you, this explained it well!
avatar
Intern
Intern
Joined: 22 Aug 2019
Posts: 9
Own Kudos [?]: 20 [0]
Given Kudos: 0
Send PM
Re: a and b are positive integers such that 4 < a + b < 6 and [#permalink]
2
a and b are positive integers such that 4<a+b<6 and |a−b|=1

A+B has to be 5 since A & B Are integers and the absolute value equation has to be equal to 1.

Two numbers that satisfy this are 2 and 3.

Now:
The volume of a cylinder with radius a and height b
The volume of a cylinder with radius b and height a

We don't know which is 2 and which is 3. The one with Radius 3 will be greater than Radius 2.

Answer D.

For completeness:

Pi(3^2)*2 = 18pi
Pi(2^2)*3= 12pi
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 3224 [0]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
a and b are positive integers such that 4 < a + b < 6 and [#permalink]
Carcass wrote:
a and b are positive integers such that \(4 < a + b < 6\) and \(| a   −   b | = 1\)


Quantity A
Quantity B
The volume of a cylinder with radius \(a\) and height \(b\)
The volume of a cylinder with radius \(b\) and height \(a\)


A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.


\(a + b = 5\)

So, we can have \(a = 1, 2, 3,\) or \(4\) and \(b = 4, 3, 2,\) or \(1\)

Also, \(|a - b| = 1\)

i.e. \(|1 - 4| = 1\)
\(|2 - 3| = 1\)
\(|3 - 2| = 1\)
\(|4 - 1| = 1\)

Col. A: \(πa^2b\)
Col. B: \(πb^2a\)

Dividing both sides by \(πab\):

Col. A: \(a\)
Col. B: \(b\)

When \(a = 2\) and \(b = 3\), Col. A < Col. B
When \(a = 3\) and \(b = 2\), Col. A > Col. B

Hence, option D
Prep Club for GRE Bot
a and b are positive integers such that 4 < a + b < 6 and [#permalink]
Moderators:
GRE Instructor
78 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

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