number properties

This topic has expert replies
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Sat Jan 28, 2012 11:35 pm
sud21 wrote:Is Z an integer?
1). Z^3 is an integer
2). Root z is an integer.
Statement 1: z³ is an integer doesn't imply that z is an integer too.
For example,
  • # z = cube root of 2 is not an integer but 2 is
    # Both z = 3 and z³ = 27 are integers
Not sufficient

Statement 2: As √z is an integer, z = (√z)² will be also an integer.

Sufficient

The correct answer is B.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/