The probability is the number of ways of placing them correctly divided by the total number of ways of placing them
First let's find how many ways the four CDs can be placed. There are four possible spots to place four CD.
The first CD has a choice of all four spots
The second CD has a choice of 3 spots (because the first CD is already placed)
The third CD has a choice of two spots
The fourth CD has to go in the remaining one spot
So there are 4*3*2*1 = 24 possible ways to order (place) four Cds.
This can also be written as 4! = 24 or four factorial equals twenty-four
Now the question is, "how many ways are there to place the CDs alphabetically by album name?"
I think that could be either one or two. A to Z is one way. A to Z or Z to A is two ways.
So the probability is either 1 out of 24 = 1/24
or 2 out of 24 = 2/24
depending on how you define "in alphabetical order".
