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
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Confused on this problem on roots.

Problem Solving — algebra and arithmetic
Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 22
Joined: Wed Apr 30, 2008 12:12 pm
Thanked: 5 times
by w0283767 » Sun Aug 22, 2010 4:11 pm
The size of a square computer screen is measured by the length of its diagonal. How much bigger is the visible area of a square 24 inch screen than the area of a 20 inch screen?

I know the formula to solve or s =d / √s

I haven't done roots in a while and am having a hard time visualizing what is going on mathematically here.

How does (24 / √2) simplify to 12√2?

I know they are equal, but am not understanding.

Thank you in advance for your time.
Top
Join the discussion
Source: — Quantitative Reasoning |
Junior | Next Rank: 30 Posts
Posts: 22
Joined: Wed Apr 30, 2008 12:12 pm
Thanked: 5 times

by w0283767 » Sun Aug 22, 2010 5:49 pm
Figured it out myself.

FYI:

To simplify 24 / √2 = (24 / √2) * (√2 / √2) = (24√2) / (√2 *√2) = 24√2 / √4 = 24√2 / 2 = 12/√2.

That is a rule I haven't used in a long time.
Top
Join the discussion
User avatar
Legendary Member
Posts: 1255
Joined: Fri Nov 07, 2008 2:08 pmFollowed by: 90 members
Location: St. Louis
Thanked: 312 times

by Tani » Mon Aug 23, 2010 8:19 am
First, the formula is the diagonal of a square divided by the square root of 2 = the side, not hte square root of s. Check out your 45/45/90 triangle.
Tani Wolff
Top
Join the discussion
Junior | Next Rank: 30 Posts
Posts: 22
Joined: Wed Apr 30, 2008 12:12 pm
Thanked: 5 times

by w0283767 » Mon Aug 23, 2010 2:52 pm
That was a typo. Thanks.
Top
Join the discussion
User avatar
Legendary Member
Posts: 1255
Joined: Fri Nov 07, 2008 2:08 pmFollowed by: 90 members
Location: St. Louis
Thanked: 312 times

by Tani » Mon Aug 23, 2010 4:44 pm
Aha! Typos are my specialty! :-)
Tani Wolff
Top
Join the discussion