Math!

[This topic has 5 member replies]
Forum Index GMAT Math Problem Solving
Free $100 Amazon.com Gift Card - Buy a GMAT course using a Beat The GMAT discount code between Mar 8-22 and get a $100 Amazon.com Gift Card. Learn more!
Post New Topic   Post Reply

bluestocking
Just gettin' started!

Default Avatar

Joined: 29 Dec 2006
Posts: 7

Thanks given: 0
Thanked 0 times in 0 posts
Location: Bombay
Topic: Math!
PostSat Dec 30, 2006 2:13 pm
Elapsed Time:
00:00
 Lap   Why a timer is critical to improving your score
My experience with the GMAT tells me that the questions on the quant section are NOT of an exceptionally tough variety - just the very SMART variety.

One must, MUST (I cannot emphasis this enough) R E A D the question properly.

Something I need to learn myself (mum's voice going 'haste makes waste' is playing in my head right now!) - Towards this end I would like to start a new thread - problems that may or may not be very tough = but require understanding (and remembering while solving) the question properly.

Lets start the series with :

PS - 1

Is |n| < 1 ?

(1) nx - n < 0

(2) x-1 = -2


(A) Statement (1) ALONE is sufficient to answer the question, but statement (2) alone is not.
(B) Statement (2) ALONE is sufficient to answer the question, but statement (1) alone is not.
(C) Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient.
(D) EACH statement ALONE is sufficient to answer the question.
(E) Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question.

(picked from MahattanGMAT)
Back to top
View user's profile Send private message
thankont
Rising GMAT Star

Default Avatar

Joined: 15 Dec 2006
Posts: 41

Thanks given: 0
Thanked 0 times in 0 posts
Location: Greece
PostSun Dec 31, 2006 6:25 am
I agree with your approach..
I think ans. is --E--
|n|<1 => -1<n<1 (this is what we are looking for
Now 1) nx-n<0 => n(x-1)<0 so either n>0 and x<1 or n<0 and x>1
(A does not hold, take for example. n=3 x=-2)
2) x-1=-2 so x=-1 (this does not say anything about n so B does not hold)
combining both statements we just get n>0 (which does not hold for ex. n=2
so I put --E--

Last edited by thankont on Mon Jan 15, 2007 1:15 am; edited 1 time in total
Back to top
View user's profile Send private message Visit poster's website
bluestocking
Just gettin' started!

Default Avatar

Joined: 29 Dec 2006
Posts: 7

Thanks given: 0
Thanked 0 times in 0 posts
Location: Bombay
PostSun Dec 31, 2006 10:09 am
hiya!

good effort, though thats not the correct ans

would you like to give it another shot before I put up the correct ans?

hint : consider + / - values for everything - including the indice (just re read the question stem - it seems like it didn't copy paste correctly and I lost the original formatting)

It should read :


Question:


Is |n| < 1 ?

(1) n^x - n < 0
(n raised to the power of x) - n < 0

(2) x^-1 = -2
(x raised to the power of -1) = -2

Hope you are able to solve it this time.
Back to top
View user's profile Send private message
aim-wsc
GMAT Titan



Joined: 20 Apr 2006
Posts: 2469

Thanks given: 144
Thanked 57 times in 45 posts
Location: BtG Underground

Target GMAT Score: 801-
PostSat Jan 13, 2007 12:06 am
Great efforts girl Smile
Nice initiative.

OK now that the question is changed altogether
Anybody want to try it one more time?

bytheway with earlier question @ post #1 thanktont's reasonings are correct. the answer should be E for that.

bluestocking wrote:
Question:


Is |n| < 1 ?

(1) n^x - n < 0
(n raised to the power of x) - n < 0

(2) x^-1 = -2
(x raised to the power of -1) = -2

Hope you are able to solve it this time.
PS:
Dear Pramila,
I am thinking of arranging an offline meet at Mumbai click here to know more
_________________
Getting started @BTG?
Beginner's Guide to GMAT | Johny learns to blog
... move on.
Back to top
View user's profile Send private message Visit poster's website
thankont
Rising GMAT Star

Default Avatar

Joined: 15 Dec 2006
Posts: 41

Thanks given: 0
Thanked 0 times in 0 posts
Location: Greece
PostMon Jan 15, 2007 1:23 am
I am not sure here but from n^x<n we see that it holds only when
0<n<1 and when x>1
from b we have that x=-1/2 so statement never holds (combining both)
so I would say --c--
Back to top
View user's profile Send private message Visit poster's website
axefx
Just gettin' started!

Default Avatar

Joined: 01 Dec 2006
Posts: 9

Thanks given: 0
Thanked 0 times in 0 posts
Location: PA, USA
PostWed Jan 17, 2007 1:56 pm
thankont wrote:
I am not sure here but from n^x<n we see that it holds only when
0<n<1 and when x>1
from b we have that x=-1/2 so statement never holds (combining both)
so I would say --c--
Would you mind explaining this:
"n^x<n we see that it holds only when
0<n<1 and when x>1 "
Back to top
View user's profile Send private message
Display posts from previous:   

Post New Topic   Post Reply All times are GMT - 7 Hours
Page 1 of 1
 
Forum Index GMAT Math Problem Solving
Most Active Members in Last 30 Days
1. harsh.champ 562 posts
2. shashank.ism 368 posts
3. thephoenix 319 posts
4. kstv 310 posts
5. ajith 279 posts
See More Top Beat The GMAT Members
Most Active Experts in Last 30 Days
1. lunarpower
Manhattan GMAT Teacher 		87 posts
2. Stuart Kovinsky
Kaplan GMAT Teacher 		63 posts
3. Lisa Anderson
Stacy Blackman Consulting 		54 posts
4. Testluv
Kaplan GMAT Teacher 		49 posts
5. Bryant@VeritasPrep
Veritas Prep 		41 posts
See More Top Beat The GMAT Experts