New Mega Millions format

The new format began drawings this week. Pick 5 of 75 (!) plus the Megaball of 15 numbers.
Here's the paytable and odds according to the site.

Match Prize Odds
5 + 1 JACKPOT 1 in 258,890,850
5 + 0 $1,000,000 1 in 18,492,204
4 + 1 $5,000 1 in 739,688
4 + 0 $500 1 in 52,835
3 + 1 $50 1 in 10,720
3 + 0 $5 1 in 766
2 + 1 $5 1 in 473
1 + 1 $2 1 in 56
0 + 1 $1 1 in 21
The overall odds of winning a prize are 1 in 14.7. The odds presented here are based on a $1 play.

I get 1 in 15 for the $1 prize, but it clearly states 1 in 21. Am I missing something very obvious here, or is this just an error?

Edit to correct typo

You need exactly 0 matches on the 5 of 75. This is a common miscalculation -- PB even has a website FAQ on it:
http://www.powerball.com/pb_contact.asp#odds

Got it.

Quote: chickenman

The new format began drawings this week. Pick 5 of 75 (!) plus the Megaball of 12 numbers.
I get 1 in 15 for the $1 prize, but it clearly states 1 in 21. Am I missing something very obvious here, or is this just an error?

For one, there are 15 numbers for the Megaball, not 12. I get 1 in 20.535 using 15.
EDIT:That's strange...the second time I do it, I get 1 in 21.3906

Using a Casio Calculator...

(75C5 / 70C5) * 15 ~= 1 in 21.39

Quote: ThatDonGuy

For one, there are 15 numbers for the Megaball, not 12. I get 1 in 20.535 using 15.
EDIT:That's strange...the second time I do it, I get 1 in 21.3906

Yep, edited to correct to 15