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 350,000 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: What is the cube root of w? [#permalink]
06 Aug 2012, 02:15

3

This post received KUDOS

Expert's post

SOLUTION

What is the cube root of w?

(1) The 5th root of w is 64 --> \(\sqrt[5]{w}=64\) --> we can find \(w\), hence we can find \(\sqrt[3]{w}\): \(w=64^5\) --> \(\sqrt[3]{w}=\sqrt[3]{64^5}\). Sufficient.

(2) The 15th root of w is 4 --> \(\sqrt[15]{w}=4\). The same here. Sufficient.

Re: What is the cube root of w? [#permalink]
06 Aug 2012, 02:31

4

This post received KUDOS

1

This post was BOOKMARKED

1. If the nth root is asked for a number X: If n is odd - It has a unique solution that satisfies. On the other hand, if n is even - then both (y)^n and (-y)^n satisfies the solution. Now to the problem: A - sufficient. 5th root - 5 odd. B - sufficient. - 15 -odd.

Re: What is the cube root of w? [#permalink]
06 Aug 2012, 06:52

1

This post received KUDOS

This is a simple Surd problem i will rate its difficulty at 500 or below. as the first step break all numbers down to their basic form 64 = 4^3 = 2^6 ( we will find later that the second part is not necessary in this question, but in some other question we might need to break down further) Lets take statement 1 : (w)^1/3 = 64 this means w = 64^3 = 4^15 = 2^30 ( stop ! much before this coz you knwo you can find it ) Second statement (w)^1/15 = 4 This means w = 4^15 = 2^30 ( Stop as soon as you know it is solvable) So choice D is the nswer.

Re: What is the cube root of w? [#permalink]
10 Aug 2012, 04:10

Expert's post

SOLUTION

What is the cube root of w?

(1) The 5th root of w is 64 --> \(\sqrt[5]{w}=64\) --> we can find \(w\), hence we can find \(\sqrt[3]{w}\): \(w=64^5\) --> \(\sqrt[3]{w}=\sqrt[3]{64^5}\). Sufficient.

(2) The 15th root of w is 4 --> \(\sqrt[15]{w}=4\). The same here. Sufficient.

safe.txmblr Can business make a difference in the great problems that we face? My own view is nuanced. I think business potentially has a significant role to play...

Still 7 months to go to be at Lausanne. But, as Lausanne has a vacancy rate of 0.1% for rental properties, I booked my rental apartment yesterday for...