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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Which of the following decribes all values of n for which

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 2544
Joined: Sun Oct 15, 2017 1:50 pmFollowed by: 6 members
by BTGmoderatorLU » Tue Sep 18, 2018 7:44 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

Source: Veritas Prep

$$\text{ Which of the following describes all values of n for which }n^2-1\ \ge0.$$
$$A.\ n\ge1$$
$$B.\ n\le1$$
$$C.\ 0\le n\le1$$
$$D.\ n\le-1\ \text{or}\ n\ge1$$
$$E.\ -1\le n\le1$$
The OA is D.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members
Location: Palo Alto, CA
Thanked: 2867 times
GMAT Score:800

by [email protected] » Tue Sep 18, 2018 7:55 pm
Hi All,

We're asked which of the following describes all values of N for which (N^2 - 1) is greater than or equal to 0. This question can be solved in a couple of different ways, but you might find it easiest to TEST VALUES.

Since we're SQUARING the value of N, we know that there will be positive values AND negative values of N that will 'fit' the given information. For example, N could be +2 or -2, so we need an answer that accounts for BOTH of those options. There's only one answer that does that....

Final Answer: D

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
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 » Wed Sep 19, 2018 6:36 am
BTGmoderatorLU wrote:Source: Veritas Prep

$$\text{ Which of the following describes all values of n for which }n^2-1\ \ge0.$$
$$A.\ n\ge1$$
$$B.\ n\le1$$
$$C.\ 0\le n\le1$$
$$D.\ n\le-1\ \text{or}\ n\ge1$$
$$E.\ -1\le n\le1$$
The OA is D.
Another approach is to test values and eliminate answer choices

For example, one value of n that satisfies the equation n² - 1 ≥ 0 is n = 2
Notice that 2² - 1 = 4 - 1 = 3 and 3 ≥ 0
Now check the answer choices. . .
Answer choice B says that n CANNOT equal 2 (since it says n ≤ 1)
As such, we can ELIMINATE B
Likewise, C and E also say that n CANNOT equal 2
So, ELIMINATE C and E

We're left with A and D

Let's find another value of n that satisfies the equation n² - 1 ≥ 0
How about n = -2
Notice that (-2)² - 1 = 4 - 1 = 3 and 3 ≥ 0
Now check the remaining answer choices. . .
Answer choice A says that n CANNOT equal -2 (since it says n ≥ 1)
As such, we can ELIMINATE B

By the process of elimination, the correct answer is D

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8136
Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members
Location: Los Angeles, CA
Thanked: 43 times

by Scott@TargetTestPrep » Sun Sep 23, 2018 3:41 pm
BTGmoderatorLU wrote:Source: Veritas Prep

$$\text{ Which of the following describes all values of n for which }n^2-1\ \ge0.$$
$$A.\ n\ge1$$
$$B.\ n\le1$$
$$C.\ 0\le n\le1$$
$$D.\ n\le-1\ \text{or}\ n\ge1$$
$$E.\ -1\le n\le1$$
The OA is D.
Simplifying, we have:

n^2 ≥ 1

|n| ≥ 1

Because this is an absolute value equation, we have two possibilities:

n ≥ 1

or

-n ≥ 1

n ≤ -1

So we have:

n ≤ -1 or n ≥ 1

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1