For USA, I first wanted to put this, but I've used names from "Countrie of the World" and in this quiz, it is "United States" so it's not ending with a vowel, but I can hear that :). For the "y", I'm not counting it as a vowel, it is a vowel, so if somebody doesn't know that, sorry for him.
Y can function as either a consonant or a vowel (see http://www.oxforddictionaries.com/words/is-the-letter-y-a-vowel-or-a-consonant) which is why you need to make clear whether you are counting it as one or the other.
Ok, you know what I think ? I'm french, in France, "y" is 100% a vowel, but this letter as the same pronunciation as the "i". Maybe in english, because "y" has a different pronunciation, it can be considered as a consonant. So I'm going to write this Thanks :)