BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

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.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
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
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start 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 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Set S consists of N elements

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 608
Joined: Sun Jun 19, 2011 11:16 amFollowed by: 8 members
Thanked: 37 times

by saketk » Fri Sep 02, 2011 2:33 pm
amsm25 wrote:Set S consists of N elements. If N>2 what is the standard deviation of S?

1) The mean and the median of the set are equal.
2) The difference between any two elements is equal.
Statement 1: -- {1,2,3,4,5} -- mean and median equal
Also, {3,3,3,3,3,3} -- Mean and median equal ..

BUT, the SD in both cases is different.. Hence STATEMENT 1 is insufficient.

Statement 2: The difference between any two elements can only be equal when all the elements are same

{1,1,1,1,1,1} or {2,2,2} etc.. Clearly, in each case SD is ZERO.

Hence, STATEMENT 2 is SUFFICIENT.

ANSWER B
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 24
Joined: Sat Aug 20, 2011 2:57 amFollowed by: 1 member
Thanked: 1 times

by samyukta » Fri Sep 02, 2011 4:39 pm
ST 1 : Mean is equal to median which means set has equally spaced elements.

It can be like : 1,2,3,4 or 2,4,6,8. Now both will have different SD.

Insufficient

ST 2: Difference between the elements should be same.... It means all elements are same.

So SD will be zero!!

Pick B
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Sat Jan 12, 2013 3:50 am

by wolfmarc » Fri Jan 09, 2015 8:00 am
Had the second statement been //2) The difference between every two elements is equal.// would the answer have been E?

Because both statements would suggest that we are grappling with an evenly spaced set, of which we ignore the number of elements.

Am I right?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Fri Jan 09, 2015 8:26 am
wolfmarc wrote:Had the second statement been //2) The difference between every two elements is equal.// would the answer have been E?

Because both statements would suggest that we are grappling with an evenly spaced set, of which we ignore the number of elements.

Am I right?
Your wording "The difference between every two elements is equal" is virtually the same as the original "the difference between any two elements is equal."

If the question stated that the elements (numbers) in set S are arranged in ASCENDING order, and statement 2 was "The difference between any two ADJACENT elements is equal," then the answer would be E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1