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

Redeem

is √ (m^2 + n^2) an integer?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

is √ (m^2 + n^2) an integer?

by sanju09 » Sat Oct 08, 2011 3:32 am
If n is an integer, is √ (m^2 + n^2) an integer?

(1) m^2 + n^2 is an integer.

(2) m^2 - 3 n^2 = 0.
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
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 Oct 08, 2011 3:49 am
sanju09 wrote:If n is an integer, is √(m^2 + n^2) an integer?

(1) m^2 + n^2 is an integer.

(2) m^2 - 3 n^2 = 0.
(1) m² + n² is an integer does not necessarily imply that √(m² + n²) is an integer; NOT sufficient.

(2) m² - 3n² = 0 implies m² = 3n² (m - n√3)(m + n√3) = 0
√(m² + n²) = √(3n² + n²) = √(4n²) = 2n, -2n
Since n is an integer, so √(m² + n²) will also be 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/
Top
Post new topic Post Reply
• Page 1 of 1