gmat prep question

[This topic has 2 member replies]

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!

« View previous topic

View next topic »

yvonne12
Really wants to Beat The GMAT!

Joined: 07 Feb 2007
Posts: 144

Thanks given: 0
Thanked 0 times in 0 posts

Topic: gmat prep question

Sun Apr 15, 2007 7:00 pm

	Elapsed Time:	00:00		Why a timer is critical to improving your score
	Lap #[LAPCOUNT] ([LAPTIME])

if z^n=1 whaty is the value of z

1. n is a non zero integer

2. z>0

I thought it was A since, z^n=1 and n is non zero z must be 1 becuase n could've been 0.

why is it both??

jayhawk2001
Moderator

Joined: 28 Jan 2007
Posts: 789

Thanks given: 0
Thanked 15 times in 14 posts
Location: Silicon valley, California

Sun Apr 15, 2007 10:00 pm

yvonne12 wrote: if z^n=1 whaty is the value of z 1. n is a non zero integer 2. z>0 I thought it was A since, z^n=1 and n is non zero z must be 1 becuase n could've been 0. why is it both?? 1 tells us that z can be +1 or -1. Based on whether n is even or odd, we can get z^n = 1. Hence insufficient. 2 tells us that z > 0 which is insufficient by itself. If n is zero, z^n =1 for any value of z > 0 Taking 1 and 2, we get z = +1. Hence C

yvonne12
Really wants to Beat The GMAT!

Joined: 07 Feb 2007
Posts: 144

Thanks given: 0
Thanked 0 times in 0 posts

Mon Apr 16, 2007 5:30 pm

yes, of course, I forgot about the sign difference. Geez thats something that I should automatically know by now.... 13 more days to go...