Easy probability questions, plz answer ASAP

[BruceZ]

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1) We have to choose a group of 5 people out ot 10(2 are married and 8 others). How many pictures are possible with 5 people if we have to include 1 person out of the married couple in the middle?(and we cant have them both in 1 picture).


[/ QUOTE ] 2*10!/6! assuming ordering matters

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If order matters it is

2*C(8,4)*4! = 3360

or 2*8!/4! = 3360

That is, 2 ways to pick the married person in the middle, times C(8,4) ways to choose the other 4 people, times 4! ways to order the other 4 people. You used C(10,4). If we only care about who is in the picture and order doesn't matter, then remove the 4! from the first expression to get 140.