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 = y, then what is the value of xy? [#permalink]

Show Tags

01 Jan 2011, 07:45

+1 for Jonblazon for good question. I got C for uncareful observation +1 for Bunuel: you are amazing Thanks once again for your good question, at least to me.
_________________

Consider giving me kudos if you find my explanations helpful so i can learn how to express ideas to people more understandable.

Re: If wx = y, then what is the value of xy? [#permalink]

Show Tags

05 Mar 2014, 08:45

Usually when I have a DS question I try to come up with the equations and respective variables that I need. Then I count the equations and unknowns and if I have more unknowns than I have equations I know it's not sufficient. Here I'm not sure if the approach is feasible, but I'd like to give it a try. Please give me your opinions on the approach:

1. We have the equation wx = y and we need to find xy = ?. In order to do so we don't need to know x or y, but only w (if we have w, we're able to find xy, as wx = y is given). Therefor w is our only unknown.

(1) we get wx^2=16. As we don't need to handle x as an unknown (see above) we can count what we have: here it's 1 unknown (w) and 1 equation => sufficient (2) we get y=4. y isn't an unknown in this approach, so when we count: 1 unknown (w) and 0 equations => not sufficient

Re: If wx = y, then what is the value of xy? [#permalink]

Show Tags

28 Oct 2015, 20:27

1

This post received KUDOS

i mistakenly took it as (wx)^2 and got wx = +-4 which is insufficient; 2 is as well insufficient.. eh..can't say it's not my fault, but the topic starter should have put the math code here :D

i mistakenly took it as (wx)^2 and got wx = +-4 which is insufficient; 2 is as well insufficient.. eh..can't say it's not my fault, but the topic starter should have put the math code here :D

The point is that wx^2 mathematically can only mean w*x^2. If it were (wx)^2 it would be written that way. Still edited to avoid confusion.
_________________

Re: If wx = y, then what is the value of xy? [#permalink]

Show Tags

29 Oct 2015, 05:55

Bunuel wrote:

mvictor wrote:

i mistakenly took it as (wx)^2 and got wx = +-4 which is insufficient; 2 is as well insufficient.. eh..can't say it's not my fault, but the topic starter should have put the math code here :D

The point is that wx^2 mathematically can only mean w*x^2. If it were (wx)^2 it would be written that way. Still edited to avoid confusion.

Thanks bunuel, but it was not needed. I admit that it was my mistake, and that I should have been more attentive. Indeed wx^2 represents w*x^2

I was speaking about \(wx^2\) rewriting in this format

Re: If wx = y, then what is the value of xy? [#permalink]

Show Tags

10 Dec 2017, 09:25

Oh my, never mind! I've been trying to read way to deep into this question and have in turn, contorted it into something else entirely in my mind. I see now, how simple it actually is. Sorry for the confusion, and thanks for clearing it up!