Oh about last day...
Yue Ying won probably because she completed all her taks. At day 1/0 she had to get us to speak spanish (i don't remember anyone doing so though, i did say "non parlo espagnol" but that's not spanish lol), then it was in spoilers (we did that), and backwards (we also did). I think that explains it.
The Zhangs were related but knew nothing. Poor Jiao even voted for Fei xD