stuck on word problem

[longdriver2]

Melody, brenda and vanghen are friends. They meet once a week for dinner. Each girl drinks Cherry cola or lemonade during the meal. If melody drinks cherry cola, then brenda drinks the beverage vaughen drinks. If brenda drinks cherry cola then melody drinks the beverage that vaughan doesn't drink. if vaughan drinks lemonade, then melody drinks the beverage that brenda drinks. THE QUESTION: which one of the girls always drinks the same beverage and which beverage does she drink?

 

[HallsofIvy]

Melody, brenda and vanghen are friends. They meet once a week for dinner. Each girl drinks Cherry cola or lemonade during the meal. If melody drinks cherry cola, then brenda drinks the beverage vaughen drinks. If brenda drinks cherry cola then melody drinks the beverage that vaughan doesn't drink. if vaughan drinks lemonade, then melody drinks the beverage that brenda drinks. THE QUESTION: which one of the girls always drinks the same beverage and which beverage does she drink?

Looks to me like you can just list the possibilities.
"If melody drinks cherry cola, then brenda drinks the beverage vaughen drinks"
So if melody drinks cola both brenda and vaughen drink cola or both drink lemonade:

m= cola, b= cola, v= cola
but this contradicts "If brenda drinks cherry cola then melody drinks the beverage that vaughan doesn't drink" and that leaves

m= cola, b= lemonade, v= lemonade.
but that contradicts "if vaughan drinks lemonade, then melody drinks the beverage that brenda drinks.

So, in fact melody cannot drink cola, she can only drink lemonade.