A group of 5 students bought movie tickets in one row next t

Question

A group of 5 students bought movie tickets in one row next to each other. If Bob and Lisa are in this group, what is the number of ways of seating if both of them will sit next to only one other student from the group?

A. 3! x 2!
B. 4! x 2!
C. 4!
D. 3!

A. 3! x 2!
B. 4! x 2!
C. 4!
D. 3!

Bunuel · Accepted Answer

The question basically asks about the # of ways that Bob and Lisa sit at the ends (only this way is valid so that both of them will sit next to only one other student).

Desired arrangement is either  B XYZ L  or  L XYZ B . Now, XYZ can be arranged in 3! ways, therefore total # of favorable arrangements is 2*3!.

Answer: A.

Bunuel · Answer

The same question about the probability: a-group-of-5-students-bought-movie-tickets-in-one-row-next-47450.html Hope this helps.

mshrek · Answer

Since there are two ends i think the answer should be 3! x 2! x 2 = 24 = 4 !

__ __ __ bob lisa , __ __ __ lisa bob = total ways = 3! x 2
bob lisa __ __ __ , lisa bob __ __ __ = total ways = 3! x 2

therefore total ways = 3! x 2 ! x 2 = 24 . Please have a relook at the OA

I am considering that both bob and lisa sit together , is my assumption wrong here ?

Bunuel · Answer

Your cases dons't satisfy the requirement that both of them will sit next to only one other student. For example, in XYZ{Bob}{Lisa}, Bob is next to both Z and Lisa.

b2bt · Answer

Your assumption is wrong.
To simplify, the question says
Lisa will sit next to only one person
Bob will sit next to only one person

__ __ __ bob lisa << bob is sitting next to 2 people lisa and some Mr. X

So if you analyze a little bit, you will realize bob and lisa can sit only on corner seats...
rest you can check Bunuel's explanation above

cledgard · Answer

This is an ambiguous question. Does the word other refer to any other student, or to another student except for Lisa and Bob?

EMPOWERgmatRichC · Answer

Hi cledgard,

The prompt tells us that the students will sit in 5 seats in a row next to one another. This means that each of the students will either sit next to just one of the other students (if seated in an "end" seat) or next to two of the other students (if seated in one of the three "middle" seats).

For Bob and Lisa to BOTH sit next to JUST ONE of the other students, then Bob and Lisa have to sit on the two "ends" of the row. In this way, Bob and Lisa CAN'T sit next to one another, so there's no ambiguity.

GMAT assassins aren't born, they're made,
Rich

sutharpralhad · Answer

Hi Bunuel ,

Kindly explain why Bob and lisa can sit  at ends only . This Case XBYLZ will also meet the requirement of question that B&L will sit next to only one other student . I interpreted it as that they will not sit together .

Thanks

Bunuel · Answer

The phrase "both of them will sit next to only one other student from the group" means Bob and Lisa each should have only one neighboring student, not two. In the XBYLZ arrangement, both Bob and Lisa are sitting next to two students each, not just one. The problem requires each to be next to only one student, which can only happen if they are at the ends.

A group of 5 students bought movie tickets in one row next t

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