How many books does it take to have 20 and 30 ap's?

Assuming no stat boosters 320 and 480 I guess?

16 * 20 = 320 and 16 * 30 = 480. AP is given on the 16th point.. you can use boosters but you must read a book on the 16th point or it won't count (until you get to the next 16th!) .. hope this helps :)

thank you you two^_^