Chris O. answered 04/19/23
Professional English and Writing Tutor with 9+ years of experience
Depends on the denomination. Protestants (using the KJV) have 66; Catholics (using the Vulgate) have 76, and Eastern Orthodox have 82, making it the most copious and also the work reliant on the oldest sources, such as the Septuagint (since it is already in Greek, one of the main languages of the Eastern Orthodox churches).
A note: Protestants use the Hebrew Bible for their Old Testament, the re-worked variant that Jewish scholars in the 2nd Century AD re-translated back into Hebrew from the Greek Septugiant as a response to the overwhelming use of the Torah for conversion to Christianity.