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interesting combinatrics question

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interesting combinatrics question

by canuckclint » Sat Oct 25, 2008 10:43 am
From MGMAT,

Sedan has 3 seats in back 2 in front like any regular sedan these days.
Dad or Mom must drive and they have 1 son and 2 daughters.
Daughters do NOT want to sit next to each other.

What are the possible seating arrangements?

Tip: It is a 2 digit answer less than 100
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by logitech » Sat Oct 25, 2008 11:20 am
Hmm..

It is either Mom or Dad who will drive the car

SO let's start with MOM driving the car:

IF Dad sits in the front: 2 sisters and the son can sit in 2 different ways. ( The guy in the middle, and the girls are on both sides)

If Son sits in the front: Same story, two possible arrangements , Dad will be in the middle and girls will be on the sides

If Daughter 1 sits in the frond: then 3x2x1= 6 different ways

If Daughter 2 sits in the front: another 6 ways

SO 2+2+6+6 = 16 possible arrangements

Samething with DAD driving the car

so 16 x 2 = 32 ?
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by canuckclint » Sat Oct 25, 2008 11:51 am
32 is one of the answers but OA will come after I finish verbal section today.
Good work.
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by logitech » Sat Oct 25, 2008 12:12 pm
canuckclint wrote:32 is one of the answers but OA will come after I finish verbal section today.
Good work.
Okay we all wait you then..Nice! ;-)
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by canuckclint » Sat Oct 25, 2008 3:15 pm
logitech wrote:
canuckclint wrote:32 is one of the answers but OA will come after I finish verbal section today.
Good work.
Okay we all wait you then..Nice! ;-)
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by canuckclint » Sat Oct 25, 2008 3:16 pm
logitech wrote:
canuckclint wrote:32 is one of the answers but OA will come after I finish verbal section today.
Good work.
Okay we all wait you then..Nice! ;-)
OA is 32

Couldn't see the answer till I completed the whole test.
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