GMATPrep CAT problem

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Tue Oct 12, 2010 3:24 am

GMATPrep CAT problem

by mshameen » Tue Feb 01, 2011 12:07 am
For all positive integers m, @m = 3m when m is odd and @m = m/2 when m is even. Which of the following is equivalent to @9 * @6?
A. 81
B. 54
C. 36
D. 27
E. 18

It looks like an easy one, but I cant believe that the GMATPrep test has my answer as incorrect. I answered choice A i.e. 81. Is this answer really incorrect? How? It needs a simple calculation
@9 * @6 = 3*9 * 6/2 = 27*3 = 81
Source: — Problem Solving |

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 » Tue Feb 01, 2011 3:29 am
mshameen wrote:For all positive integers m, @m = 3m when m is odd and @m = m/2 when m is even. Which of the following is equivalent to @9 * @6?
A. 81
B. 54
C. 36
D. 27
E. 18
In the original GMAT Prep question the options are :
  • A. @81
    B. @54
    C. @36
    D. @27
    E. @18
Hence, @9 * @6 = (27)*(3) = @27

The correct answer is D.
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/

Junior | Next Rank: 30 Posts
Posts: 11
Joined: Tue Oct 12, 2010 3:24 am

by mshameen » Tue Feb 01, 2011 4:54 am
Thats tricky...I wonder how it didnt strike me even while copying the question. Thanks a ton!!