Last visit was: 21 Nov 2024, 16:47 It is currently 21 Nov 2024, 16:47

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: 30003
Own Kudos [?]: 36341 [10]
Given Kudos: 25927
Send PM
Most Helpful Community Reply
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12196 [5]
Given Kudos: 136
Send PM
General Discussion
avatar
Intern
Intern
Joined: 17 Jul 2017
Posts: 15
Own Kudos [?]: 10 [0]
Given Kudos: 0
Send PM
Verbal Expert
Joined: 18 Apr 2015
Posts: 30003
Own Kudos [?]: 36341 [0]
Given Kudos: 25927
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
Expert Reply
avatar
Intern
Intern
Joined: 23 Nov 2017
Posts: 45
Own Kudos [?]: 87 [2]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
2
I am not sure mine was the best approach but it did work.

Just by looking at the denominators, we know d will not be equal 0 or 2 because if d = (0 or 2), the denominators would be 0 which is undefined.

What happens if d is a positive number?

if d = 1 then you end up with 2 = -1 which is false.
If d is greater than 2, then 2/d will ALWAYS be a positive number. The numerator (2-d) will ALWAYS be a negative number and the denominator (d-2) will ALWAYS be a positive number. Since a positive number divided by a negative number always equals a negative number, you know d cannot be a positive number since d/2 is positive and 2-d/d-2 is negative.

What if d is less than 0?

When d is a negative number, 2/d will ALWAYS be negative. The numerator (2 - d) will ALWAYS be a positive number. The denominator (d - 2) will ALWAYS be negative. A positive number divided by a negative number will always be negative.

We do not know what d will be, but at least we know it will be a negative number because that is the only way both sides of the equation will have the same sign. Since 0 is more than any negative number, we can conclude quantity b is bigger.

I hope i didn't make a mistake here. If I did, I apologize in advance.
avatar
Intern
Intern
Joined: 11 Jan 2018
Posts: 44
Own Kudos [?]: 104 [0]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
1
Great question.
It was tricky one.
Answer is B.

After solving the equation, we'll get
either d = 2 or d = -2

But d cannot be equals to 2, because the equation will become undefined.

Thus d = -2

So, Quantity B is greater.
Choice B correct.

Originally posted by GREMasterBlaster on 01 Mar 2018, 04:48.
Last edited by GREMasterBlaster on 04 Mar 2018, 01:42, edited 1 time in total.
User avatar
Manager
Manager
Joined: 26 Jun 2017
Posts: 102
Own Kudos [?]: 71 [0]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
great question, thanks, I just unconscionably assumed that it's D, since the d yielded -+2.
avatar
Intern
Intern
Joined: 04 Dec 2018
Posts: 30
Own Kudos [?]: 20 [0]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
tricky question. I thought we could not do cross multiplication due to being unsure whether denominator was going to be 0 or not. It turns out we need to assume it's not going to be 0.
Intern
Intern
Joined: 09 Dec 2018
Posts: 41
Own Kudos [?]: 34 [4]
Given Kudos: 29
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
4
(a-b)/(b-a) is always equal to -1, so it simplifies to 2/d = -1, which means d is negative. Answer B.
avatar
Supreme Moderator
Joined: 01 Nov 2017
Posts: 371
Own Kudos [?]: 470 [4]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
4
Expert Reply
Carcass wrote:

This question is part of GREPrepClub - The Questions Vault Project



\(\frac{2}{d}= \frac{2-d}{d-2}\)


Quantity A
Quantity B
d
0


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.


You can cross multiply as shown above or range fractions to get the answer straight..
\(\frac{2}{d}= \frac{2-d}{d-2}\)..
\(\frac{2}{d}= \frac{-(d-2)}{(d-2)}\)=-1..
So \(\frac{2}{d}=-1\)..
Only possibility is d=-2

Hence B
avatar
Intern
Intern
Joined: 26 Apr 2020
Posts: 14
Own Kudos [?]: 11 [2]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
2
\(\frac{2-d}{d-2}\) will always equal -1.

Try some values for that: Regardless whether positive, negative or 0, it will equal -1 (as both signs are inversed)


So, \(\frac{2}{d}\) = -1
Therefore, d=-2 and -2<0, hence answer B
avatar
Manager
Manager
Joined: 29 Apr 2020
Posts: 67
Own Kudos [?]: 9 [0]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
why would not the answer be D?
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12196 [0]
Given Kudos: 136
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
Nikhil4GRE wrote:
why would not the answer be D?


D) The relationship cannot be determined from the information given.

To show that the answer is D, you must identify two values of d that yield conflicting comparisons (e.g., in one case Quantity A is greater, and in the other case Quantity B is greater)
Manager
Manager
Joined: 03 Nov 2021
Posts: 92
Own Kudos [?]: 101 [1]
Given Kudos: 17
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
1
\(\frac{2}{d} = \frac{2-d}{d-2}\)

\(\frac{2}{d} = \frac{2-d}{-(2-d)}\)

\(\frac{2}{d} = -\frac{2-d}{2-d} = -1\)

\(2 = -d\)

\(d = -2\)

Hence, answer is B
Manager
Manager
Joined: 10 Feb 2023
Posts: 76
Own Kudos [?]: 13 [0]
Given Kudos: 172
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
Hi Brent GreenlightTestPrep, question do not state d is positive/negative. Do we not need to concern about this before cross multiplication in this case? Thanks
Verbal Expert
Joined: 18 Apr 2015
Posts: 30003
Own Kudos [?]: 36341 [0]
Given Kudos: 25927
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
Expert Reply
The LHS and the RHS must be equal and d must be different from zero.

In this scenario you can cross multiply regardless
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 5030
Own Kudos [?]: 74 [0]
Given Kudos: 0
Send PM
Re: 2/d= 2-d/d-2 [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep 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.
Prep Club for GRE Bot
Re: 2/d= 2-d/d-2 [#permalink]
Moderators:
GRE Instructor
84 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

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