It is currently 23 Aug 2017, 10:39

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If xy>0, which of the following must be positive?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Revolution GMAT Instructor
User avatar
G
Joined: 16 Aug 2015
Posts: 3826

Kudos [?]: 2521 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
If xy>0, which of the following must be positive? [#permalink]

Show Tags

New post 14 Apr 2017, 07:39
Expert's post
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

97% (01:30) correct 3% (01:55) wrong based on 33 sessions

HideShow timer Statistics

If xy>0, which of the following must be positive?

A. \(x\)
B. \(y\)
C. \(x^2y\)
D. \(y^2x\)
E. \(x^3y\)
[Reveal] Spoiler: OA

_________________

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
See our Youtube demo

Kudos [?]: 2521 [0], given: 0

Manager
Manager
avatar
G
Joined: 18 Jan 2017
Posts: 74

Kudos [?]: 58 [0], given: 356

Location: India
Concentration: Finance, Economics
GMAT 1: 700 Q50 V34
GMAT ToolKit User CAT Tests
Re: If xy>0, which of the following must be positive? [#permalink]

Show Tags

New post 14 Apr 2017, 08:05
xy>0, implies both x and y are of the same sign
Only option E satisfies, remaining are dependent on sign of x,y
x^3y is positive provided both x and y are of the same sign

Kudos [?]: 58 [0], given: 356

Expert Post
Math Revolution GMAT Instructor
User avatar
G
Joined: 16 Aug 2015
Posts: 3826

Kudos [?]: 2521 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: If xy>0, which of the following must be positive? [#permalink]

Show Tags

New post 16 Apr 2017, 18:30
==> Squares are always positive, so the inequality sign doesn’t change even if you multiply or divide. Thus, from xy>0 and \((x^2)xy>(x^2)0\), you get \(x^3y>0\).

The answer is E.
Answer: E
_________________

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
See our Youtube demo

Kudos [?]: 2521 [0], given: 0

Re: If xy>0, which of the following must be positive?   [#permalink] 16 Apr 2017, 18:30
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic If xy>0, which of the following must be positive? Bunuel 8 21 May 2017, 01:44
1 Experts publish their posts in the topic If n > 0 , which of the following must be true? Bunuel 3 12 May 2016, 09:37
39 Experts publish their posts in the topic If xy > 0 and yz < 0, which of the following must be negativ Bunuel 15 16 Apr 2017, 06:35
2 Experts publish their posts in the topic Given that xy > 0, which of the following must also be mikemcgarry 4 25 Dec 2015, 09:25
26 Experts publish their posts in the topic If xy > 0 and yz < 0, which of the following must be negativ GMAThirst 12 12 May 2017, 03:20
Display posts from previous: Sort by

If xy>0, which of the following must be positive?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.