At a certain bookstore, the best-selling book, "TOP," costs $8. The least-selling book, "ABC," costs $23. Thirteen "TOP" books and four "ABC" books were sold last week. What is the difference in the bookstore's earnings on these two books last week?
On "TOP" books the bookstore made 13 * 8 = $<<13*8=104>>104.
The "ABC" books, on the other hand, were sold for a total of 4 * 23 = $<<4*23=92>>92.
The difference between earnings from these two books is 104 - 92 = $<<104-92=12>>12.
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