perm & combinations

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perm & combinations

by punitkaur » Mon Nov 02, 2009 11:03 am
. A computer game has five difficulty levels. In each level you can choose among four different scenarios except for the first level, where you can choose among three scenarios only. How many different games are possible?

a) 18
b) 19
c) 20
d) 21
e) None of the above

My ans is 4x4x4x4x3.

however, the ans adds those values rather than multiply.
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by venubab » Wed Nov 04, 2009 1:49 am
Answer is 4x4x4x4x3

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Re: perm & combinations

by life is a test » Wed Nov 04, 2009 2:44 am
punitkaur wrote:. A computer game has five difficulty levels. In each level you can choose among four different scenarios except for the first level, where you can choose among three scenarios only. How many different games are possible?

a) 18
b) 19
c) 20
d) 21
e) None of the above

My ans is 4x4x4x4x3.

however, the ans adds those values rather than multiply.
the question is not asking about the different order you can play the game in (e.g. play difficulty 4 and scenario 3 first vs playing difficulty 2 and scenario 1 first etc.) but rather the different num of unique games that are possible. in the attached there are only 19 different branches (i.e. unique games) irrespective of how you order these branches.

hope that helps.
Attachments
games.JPG

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by venubab » Wed Nov 04, 2009 3:11 am
You are right