Let \(x\) represent the number of comic books on each shelf before his father added the 20 books to the bottom shelf. Since there are 5 shelves, the total number of books initially in the collection can be represented as:
\[ 5x \]
After his father adds 20 comic books to the bottom shelf, the number of books on that shelf becomes:
\[ x + 20 \]
According to the problem, after this addition, the bottom shelf has 125 books. Thus, we can set up the equation:
\[ x + 20 = 125 \]
Next, we solve for \(x\):
\[ x = 125 - 20 \] \[ x = 105 \]
Now that we know there are 105 comic books on each shelf initially, we can find the total number of comic books in the collection:
\[ 5x = 5 \times 105 = 525 \]
Thus, the total number of comic books in Jose's collection is:
\[ \boxed{525} \]
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