SOLUTION: For a segment of a radio​ show, a disc jockey can play 6 records. If there are 9 records to select​ from, in how many ways can the program for this segment be​ ar

Algebra ->  Permutations -> SOLUTION: For a segment of a radio​ show, a disc jockey can play 6 records. If there are 9 records to select​ from, in how many ways can the program for this segment be​ ar      Log On


   

Question 1107627: For a segment of a radio​ show, a disc jockey can play 6 records. If there are 9 records to select​ from, in how many ways can the program for this segment be​ arranged?
Found 2 solutions by addingup, greenestamps:
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
When order doesn't matter:
9C6 = n!/(n-r)! = 9!/(9-6)! = 362880/6 = 60480

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The response from the other tutor is confusing; he seems to be saying that order does not matter, but then his answer is if order DOES matter.

Since the question asks how many ways the program be arranged, to me that implies that order does matter. Then the number of ways is

P(9,6) = 9*8*7*6*5*4 = 60480.

If the question was intended only to ask which 6 of the 9 songs he could choose, with order not being important, then the number would be C(9,6) = C(9,3) = (9*8*7)/(3*2*1) = 84.