It is currently 10 Dec 2018, 12:04
My Tests

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.

The value of P if V = 20 and T = 32

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Moderator
Moderator
User avatar
Joined: 18 Apr 2015
Posts: 5126
Followers: 76

Kudos [?]: 1028 [0], given: 4631

CAT Tests
The value of P if V = 20 and T = 32 [#permalink] New post 13 Sep 2017, 12:38
Expert's post
00:00

Question Stats:

58% (00:59) correct 41% (01:15) wrong based on 24 sessions



For a certain quantity of a gas, pressure P, volume V, and temperature T are related according to the formula PV = kT, where k is a constant.

Quantity A
Quantity B
The value of P if V = 20 and T = 32
The value of T if V = 10 and P = 78


A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

_________________

Get the 2 FREE GREPrepclub Tests


Last edited by Carcass on 04 Oct 2017, 05:36, edited 2 times in total.
Edited by Carcass
1 KUDOS received
Director
Director
Joined: 03 Sep 2017
Posts: 521
Followers: 1

Kudos [?]: 330 [1] , given: 66

Re: The value of P if V = 20 and T = 32 [#permalink] New post 16 Sep 2017, 08:40
1
This post received
KUDOS
I've put D because it seemed a nonsense question to me. Is it like that on purpose or is some formula missing? Otherwise, how can I know the value of a variable given two others without knowing their relationship?
1 KUDOS received
Moderator
Moderator
User avatar
Joined: 18 Apr 2015
Posts: 5126
Followers: 76

Kudos [?]: 1028 [1] , given: 4631

CAT Tests
Re: The value of P if V = 20 and T = 32 [#permalink] New post 16 Sep 2017, 15:51
1
This post received
KUDOS
Expert's post
Sorry. I do apologize. I should add the stimulus but internet related problems have been fighting against me.

Regards
_________________

Get the 2 FREE GREPrepclub Tests

Director
Director
Joined: 03 Sep 2017
Posts: 521
Followers: 1

Kudos [?]: 330 [0], given: 66

Re: The value of P if V = 20 and T = 32 [#permalink] New post 21 Sep 2017, 07:52
Using the formula, then we have that column A is equal to \(P=\frac{8}{5}k\) and column B is equal to \(T=\frac{780}{k}\). Comparing those two quantities and simplifying we finally reach a comparison between \(k^2\) and 487.5. Given that k can be whatever constant, we can't say which one of the two is the greatest, thus answer is D!
Manager
Manager
Joined: 09 Nov 2018
Posts: 69
Followers: 0

Kudos [?]: 5 [0], given: 1

CAT Tests
Re: The value of P if V = 20 and T = 32 [#permalink] New post 13 Nov 2018, 06:45
IlCreatore wrote:
Using the formula, then we have that column A is equal to \(P=\frac{8}{5}k\) and column B is equal to \(T=\frac{780}{k}\). Comparing those two quantities and simplifying we finally reach a comparison between \(k^2\) and 487.5. Given that k can be whatever constant, we can't say which one of the two is the greatest, thus answer is D!


Just an example:
If k=0, a=0 b=undefined
k=1 makes a=1.6 b=780
so answer D.
1 KUDOS received
GRE Instructor
User avatar
Joined: 10 Apr 2015
Posts: 1232
Followers: 45

Kudos [?]: 1110 [1] , given: 7

Re: The value of P if V = 20 and T = 32 [#permalink] New post 13 Nov 2018, 06:57
1
This post received
KUDOS
Expert's post
Carcass wrote:



For a certain quantity of a gas, pressure P, volume V, and temperature T are related according to the formula PV = kT, where k is a constant.

Quantity A
Quantity B
The value of P if V = 20 and T = 32
The value of T if V = 10 and P = 78



QUANTITY A: The value of P if V = 20 and T = 32
Take given formula, PV = kT, and plug in values to get: P(20) = k(32)
Divide both sides by 20 to get: P = 32k/20
Simplify to get: P = 8k/5

QUANTITY B: The value of T if V = 10 and P = 78
Take given formula, PV = kT, and plug in values to get: (78)(10) = kT
Divide both sides by k to get: (78)(10)/k = T
Simplify to get: T = 780/k

So, we have:
QUANTITY A: 8k/5
QUANTITY B:780/k


Let's TEST some possible values of k

Try k = 1
In this case, we get:
QUANTITY A: 8k/5 = (8)(1)/5 = 8/5
QUANTITY B:780/k = 780/1 = 780
In this case, QUANTITY B IS GREATER

Try k = 1000
In this case, we get:
QUANTITY A: 8k/5 = (8)(1000)/5 = some number greater than 1
QUANTITY B:780/k = 780/1000 = some number less than 1
In this case, QUANTITY A IS GREATER

Answer: D

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com
Image
Sign up for our free GRE Question of the Day emails

Intern
Intern
Joined: 02 Oct 2018
Posts: 31
Followers: 0

Kudos [?]: 2 [0], given: 0

CAT Tests
Re: The value of P if V = 20 and T = 32 [#permalink] New post 13 Nov 2018, 08:34
The answer is D.
In the first case it becomes P=1.6k whereas in the second case it becomes 780/k.

Since we don't know k we can't determine the answer.
Re: The value of P if V = 20 and T = 32   [#permalink] 13 Nov 2018, 08:34
Display posts from previous: Sort by

The value of P if V = 20 and T = 32

  Question banks Downloads My Bookmarks Reviews Important topics  


GRE Prep Club Forum Home| About| Terms and Conditions and Privacy Policy| GRE Prep Club Rules| Contact

Powered by phpBB © phpBB Group

Kindly note that the GRE® test is a registered trademark of the Educational Testing Service®, and this site has neither been reviewed nor endorsed by ETS®.