So, I was looking for a cool bandana to have, and then I decided to seek after the Raven Ninja bandana, which is available at Crimsonwood Exchange Quest. In this exchange quest, you exchange 2 crimson hearts for one out of 11 equipments, like Spirit Taru Capu, White Identity, Raven Ninja bandana...

So, I got 234 Crimson Hearts (I got 72 first, then 62 then 100) and I used them to turn on the exchange quest 117 times. That means I got 117 equipments from the exchange quest.

The problem is, I got 10 out of 11 equips, and I got these 10 equips multiple times. On the other hand, I didn't get any Raven Ninja Bandana. If all the equipa have the same chance to be rewarded at the exchange quest, every equip has approximately 9,09% chance of being rewarded, and there's approximately 90,91% of a certain item not be rewarded. That way, if we look at the situation as a whole, I had 0,9091 ^ 117 = 0.00001437354 -> 0,0001437354% chance of not being rewarded a certain item atleast 1 time in 117 times. In fact, I didn't get any Raven Ninja bandana after these 117 tries. So I think there could be 3 situations:

1° - I've hit the unlucky jackpot, and I just got into that 0,0001437354% chance. It's possible, but it is REALLY difficult to be part of that chance

2° - Intentionally or unintentionally, the chance of Raven Ninja bandana getting rewarded at this exchange quest is far, far lower than all the others equipments

3° - The Raven Ninja bandana isn't available as a prize of this exchange quest, contrary to those patch notes: http://maplestory.nexon.net/news/2695/v-146-return-to-masteria-patch-notes

My question is: which of these 3 cases is the correct one?