Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

What is the cubed root of W?

Expert replies
by maggiejdyer » Sun Mar 01, 2015 5:51 pm
DS:

What is the cubed root of W?

1) the 5th root of W is 64.
2) the 15th root of W is 4.

Can someone show the algebra here? I am not following the OG's explanation.

Thanks!
Join the discussion
Source: — Problem Solving |

by DavidG@VeritasPrep » Sun Mar 01, 2015 6:08 pm
First, the xth root of w will just be w^(1/x)


1) the 5th root of W is 64.
This tells us that w^(1/5) = 64. So w = 64^5. We have w, so sufficient.



2) the 15th root of W is 4
This tells us that w^(1/15) = 4. So w = 4^15. Again, we have w, so sufficient.
Veritas Prep | GMAT Instructor

Veritas Prep Reviews
Save $100 off any live Veritas Prep GMAT Course
Join the discussion

by DavidG@VeritasPrep » Sun Mar 01, 2015 6:41 pm
And if we actually wanted to solve for the cubed root of w, or w^(1/3):

S1: w = 64^5. Because 64 = 2^6, we can rewrite 64^5 as (2^6)^5 = 2^30.
(2^30)^(1/3) = 2^10


S2: w = 4^15, we can rewrite as (2^2)^15 = 2^30.
Again, (2^30)^(1/3) = 2^10

But for DS, it's enough to see that if we can solve for w, we can get a unique value for w^(1/3)
Veritas Prep | GMAT Instructor

Veritas Prep Reviews
Save $100 off any live Veritas Prep GMAT Course
Join the discussion

by Matt@VeritasPrep » Mon Mar 02, 2015 3:57 pm
As for how to solve each one, the algebra looks like this:

S1:: �√w = 64. Raising both sides to the fifth gives w = 64�.
S2:: ¹�√w = 4. Raising both sides to the fifteenth gives w = 4¹�.

Notice too that these are the same number: 64� = (4³)� = 4¹�.
Join the discussion