PotterMore: Early Access Answers Day 6

Edit: This morning’s registration is now closed. Please come back tonight at 7:30pm – 10pm EST for the final chance at gaining early access.

Want early access to PotterMore.com? Each day I will post the solution to finding The Magical Quill.

Day 6 clue:
How many chapters are there in HARRY POTTER and the Half-Blood Prince?
Multiply this number by 14.

[spoiler]30 x 14 = 420

Go to http://quill.pottermore.com/420