Z^N = 1

This topic has expert replies
Source: — Data Sufficiency |

Legendary Member
Posts: 621
Joined: Wed Apr 09, 2008 7:13 pm
Thanked: 33 times
Followed by:4 members

by vittalgmat » Mon Nov 10, 2008 1:54 pm
z^n =1

From 1.
n is non-zero so could be -ve or +ve int.
possibilities are 1^1, 1^2, 1^(-2), (-1)^2, (-1)^(any even int)
So z = {1, -1} Not sufficient


From 2. z > 0.
anynumber ^ 0 = 1. So any number +ve, -ve raised to 0th power is 1.
So not sufficient.

Combine 1 and 2.
We get 1^anynumber = 1. So z =1

Answer is C

HT Helps
-V

Senior | Next Rank: 100 Posts
Posts: 65
Joined: Sun Oct 19, 2008 2:18 pm
Thanked: 1 times

Re: Z^N = 1

by yezz » Mon Nov 10, 2008 2:10 pm
Geisslerbg wrote:If Z^N = 1, what is the value of Z?

1) n is a non zero integer
2) Z > 0

if n is 0 then z can be any number

if n not 0 then z can be either 1 or -1 depending on wheather n is even or odd

from 1

n is not zero........insuff

from 2

z> 0 .....insuff

both toegther

z = 1 ..........C