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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: If wx>0, xy>0, and yz<0, is w^3*z^2<0? 1) z>0 2) x<0 [#permalink]

Show Tags

10 Mar 2017, 00:43

wx>0, xy>0 and yz<0. This condition holds true if w,x,y are of same sign and z is of opposite sign There fore in order to answer the question, we need the sign of atleast one variable.

St 1: z is negative. that means w,x,y are positive. therefore w^3 will be positive and z^2 will be positive and hence w^3.z^2 will be positive. ANSWER St 2: x is negative. that means w and y are negative and z is positive. hence w^3 is negative and z^2 is positive. Hence w^3.z^2 will be negative. ANSWER

Re: If wx>0, xy>0, and yz<0, is w^3*z^2<0? 1) z>0 2) x<0 [#permalink]

Show Tags

14 Sep 2017, 13:12

My approach - marked it wrong initially, but then realized why it is D: 1) z > 0 --> y * z < 0 means y is -ve and z is +ve --> indicates only case of -x *-y>0 and - w*-x>0 --> therefore z sq*w cube <0

2) x<0 --> only case of -x*-y >0 --> -x*-w> 0 (only case possible) --> -y*z< 0 (carrying over the sign for y) --therefore w cube * z sq < 0 suff