Question

How many Percy Jackson books are there?
What are they Called? [Optional].

Answer 1

Five supplementary books, along with three graphic novels, have also been released.Percy Jackson & the Olympians, often shortened to Percy Jackson, is a pentalogy of fantasy adventure novels written by American author Rick Riordan, and the first book series in the Camp Half-Blood Chronicles. 

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Answer 2

HEY USER,
HERE IS YOUR ANSWER :-

There are total 5 Percy Jackson books .
These are :-

1) The lightning thief

2) The sea of monsters

3) The Titan's curse

4) The battle of lybrinth

5) Percy Jackson and the last Olympian

HOPE IT HELPS YOU !!!......✌️✌️✌️✌️