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one more before going to bed...permutation?

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one more before going to bed...permutation?

by EddieU » Thu Jun 16, 2011 7:32 pm
Is there any easy way to memorize this? I always get confused with these kind of questions:

In how many different ways can 3 people be assigned to fill 3 different positions so that each person is assigned to exactly one position?
(A) Twelve
(B) Nine
(C) Six
(D) Three
(E) One

correct answer: c.

Thanks in advance
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by thephoenix » Thu Jun 16, 2011 7:39 pm
the easiest way is to solve in a laymen's method
for 1st person we have 3 choices so in 3 ways
for second we have 2
for last there is only one

tot ways 3*2*1=6
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by amit2k9 » Thu Jun 16, 2011 7:45 pm
let the positions be x,y,z
let the people be a,b,c

now x has 3 people to be assigned
y has 2 and z has only 1

thus 3*2*1 = 6
C
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by MBA.Aspirant » Thu Jun 16, 2011 9:42 pm
You have 3 people and 3 positions

Position 1 can be decided in 3 ways (3 people)
Position 2 in 2 ways
Position 3 in 1 way

Total = 3*2*1 = 6 ways
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