You meet a ghost and he tells you his story. He crashed the party last year and stole some candy. He was caught and cursed to become the creature he was dressed as. He offers you a deal, if you can solve his riddle, he will show you the secret escape route.

The ghost tells you that after becoming a ghost, he haunted his friends for a while just for fun. During this time, he managed to contact them and leave a message to each.
One friend was told the type of candy the ghost stole while the other was told the amount of candy that was taken. The ghost proceeds to give you a list of 10 possibilities and what the friends had to say about it:

5 Gummies
9 Gummies
13 Gummies
6 Cake pops
20 Cake pops
 
9 Chocolate bars
11 Chocolate bars
 
5 Jelly Beans
11 Jelly Beans
20 Jelly Beans

Frankie: I don't know the exact loot but I know which candy was taken. I know that Diana doesn't know the exact loot either.
Diana: At first I didn't know either, but now I know.
Frankie: Ahh! Based on what Diana said, I know it too now!