It is currently 01 Dec 2020, 00:18

### 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

# If |a/b| and |x/y| are reciprocals and

Author Message
TAGS:
Founder
Joined: 18 Apr 2015
Posts: 13927
GRE 1: Q160 V160
Followers: 315

Kudos [?]: 3687 [1] , given: 12946

If |a/b| and |x/y| are reciprocals and [#permalink]  12 Aug 2018, 09:54
1
KUDOS
Expert's post
00:00

Question Stats:

76% (01:10) correct 23% (01:24) wrong based on 106 sessions
If $$|\frac{a}{b}|$$ and $$|\frac{x}{y}|$$ are reciprocals and $$\frac{a}{b} (\frac{x}{y}) < 0$$, which of the following must be true?

A. $$ab < 0$$

B. $$\frac{a}{b} (\frac{x}{y}) < -1$$

C. $$\frac{a}{b} < 1$$

D. $$\frac{a}{b} = \frac{-y}{x}$$

E. $$\frac{y}{x} > \frac{a}{b}$$
[Reveal] Spoiler: OA

_________________

New to the GRE, and GRE CLUB Forum?
GRE: All you do need to know about the GRE Test | GRE Prep Club for the GRE Exam - The Complete FAQ
Posting Rules: QUANTITATIVE | VERBAL
FREE Resources: GRE Prep Club Official LinkTree Page | Free GRE Materials - Where to get it!! (2020)
Free GRE Prep Club Tests: Got 20 Kudos? You can get Free GRE Prep Club Tests
GRE Prep Club on : Facebook | Instagram

Questions' Banks and Collection:
ETS: ETS Free PowerPrep 1 & 2 All 320 Questions Explanation. | ETS All Official Guides
3rd Party Resource's: All Quant Questions Collection | All Verbal Questions Collection
Books: All GRE Best Books
Scores: The GRE average score at Top 25 Business Schools 2020 Ed. | How to study for GRE retake and score HIGHER - (2020)
How is the GRE Score Calculated -The Definitive Guide (2021)
Tests: GRE Prep Club Tests | FREE GRE Practice Tests [Collection] - New Edition (2021)
Vocab: GRE Prep Club Official Vocabulary Lists for the GRE (2021)

Intern
Joined: 10 Sep 2018
Posts: 20
Followers: 0

Kudos [?]: 26 [2] , given: 9

Re: If |a/b| and |x/y| are reciprocals and [#permalink]  13 Sep 2018, 12:32
2
KUDOS
using the definition of absolute values, we can say a/b is either y/x or -y/x. but as the second condition implies, these two fractions hold opposite signs.

so a/b=-y/x
GRE Instructor
Joined: 10 Apr 2015
Posts: 3914
Followers: 164

Kudos [?]: 4781 [1] , given: 70

Re: If |a/b| and |x/y| are reciprocals and [#permalink]  10 Jun 2020, 16:34
1
KUDOS
Expert's post
Carcass wrote:
If $$|\frac{a}{b}|$$ and $$|\frac{x}{y}|$$ are reciprocals and $$\frac{a}{b} (\frac{x}{y}) < 0$$, which of the following must be true?

A. $$ab < 0$$

B. $$\frac{a}{b} (\frac{x}{y}) < -1$$

C. $$\frac{a}{b} < 1$$

D. $$\frac{a}{b} = \frac{-y}{x}$$

E. $$\frac{y}{x} > \frac{a}{b}$$

We can either try to apply some number sense or simply test some values.

I have a feeling the latter might be faster.

If |a/b| and |x/y| are reciprocals, AND (a/b)(x/y) < 0, then it could be the case that: a = 1, b = 1, x = 1 and y = -1

Now check out the choices....

A. $$(1)(1) < 0$$ NOT TRUE

B. $$\frac{1}{1} (\frac{1}{-1}) < -1$$ NOT TRUE

C. $$\frac{1}{1} < 1$$ NOT TRUE

D. $$\frac{1}{1} = \frac{-(-1)}{1}$$ TRUE!

E. $$\frac{-1}{1} > \frac{1}{1}$$ NOT TRUE

Cheers,
Brent
_________________

Brent Hanneson – Creator of greenlighttestprep.com

Intern
Joined: 22 Oct 2019
Posts: 11
Followers: 0

Kudos [?]: 2 [0], given: 3

Re: If |a/b| and |x/y| are reciprocals and [#permalink]  28 Oct 2020, 23:39
As, (a/b)(x/y)<1; one of the terms (a/b) or (x/y) must be negative.
Again, MOD(a/b)=1/MOD(x/y)= MOD(y/x).......(i)
When, (a/b)=-ve; MOD(a/b)= -(a/b), then y/x must be positive.
From (i) we get, -(a/b)= (x/y)
Intern
Joined: 18 Oct 2020
Posts: 5
Followers: 0

Kudos [?]: 4 [0], given: 0

Re: If |a/b| and |x/y| are reciprocals and [#permalink]  07 Nov 2020, 02:14
Quote:
If |a/b| and |x/y| are reciprocals, AND (a/b)(x/y) < 0, then it could be the case that: a = 1, b = 1, x = 1 and y = -1

Doesn't a or b have to be negative if a/b and x/y are reciprocals? a/b is the multiplicative inverse of x/y and a/b * x/y must equal 1. 1/1 * 1/-1 = -1

correct oa should be A and C
Re: If |a/b| and |x/y| are reciprocals and   [#permalink] 07 Nov 2020, 02:14
Display posts from previous: Sort by