perm & combinations

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punitkaur
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Topic: perm & combinations
PostMon Nov 02, 2009 11:03 am Reply with quote
. 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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venubab
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PostWed Nov 04, 2009 1:49 am Reply with quote
Answer is 4x4x4x4x3
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PostWed Nov 04, 2009 2:44 am Reply with quote
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.
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venubab
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PostWed Nov 04, 2009 3:11 am Reply with quote
You are right
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