SOLUTION: You own 18 CDs. You want to randomly arrange 10 of them in a CD rack. What is the probibility that the rack ends up in alphabetical order? Please show steps I must be missing somet
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-> SOLUTION: You own 18 CDs. You want to randomly arrange 10 of them in a CD rack. What is the probibility that the rack ends up in alphabetical order? Please show steps I must be missing somet
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Question 1148330: You own 18 CDs. You want to randomly arrange 10 of them in a CD rack. What is the probibility that the rack ends up in alphabetical order? Please show steps I must be missing something. Thanks in advance. Answer by ikleyn(52790) (Show Source):
The number of all possible arrangements of 18 CDs is the number of all permutations of 18 items, i.e.
18! = 1*2*3*4*5*6*7*8*9*10*11*12*13*14*15*16*17*18.
Only one of these permutations is in alphabetical order.
Therefore, the probability that the rack ends up in alphabetical order is equal to
P = . ANSWER
To get the numerical value, use a calculator.
