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

Redeem

help with combination problem.

Expert replies
by galaxis09 » Sun Nov 06, 2011 2:50 pm
can someone please help me out with this question.
In how many ways can Ann, Bea, Cam, Don, Ella and Fey be seated if Ann and Bea cannot be seated next to each other?
(A) 240 (B) 360(C) 480(D) 600(E) 720.
Join the discussion
Source: — Problem Solving |

by neelgandham » Sun Nov 06, 2011 3:03 pm
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/
Join the discussion

by Anurag@Gurome » Sun Nov 06, 2011 8:10 pm
galaxis09 wrote:can someone please help me out with this question.
In how many ways can Ann, Bea, Cam, Don, Ella and Fey be seated if Ann and Bea cannot be seated next to each other?
(A) 240 (B) 360(C) 480(D) 600(E) 720.
Total ways of seating 6 people = 6!
Consider Ann and Bea as one person, then number of ways of arranging 5 people = 5!
Number of ways of arranging Ann and Ben = 2!
Required number of ways of seating 6 people if Ann and Bea are not seated next to each other = 6! - 5!2! = 720 - 240 = 480

The correct answer is C.
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/
Join the discussion