Student or Learner
I saw one person writing under his pictures in Facebook: Mixed of old and new. He meant that it consists of old and new pictures.
For me, I should be "mixture of new and old pictures", because the profile is a noun and "mixture" would be correct to denote that.
Is my understanding correct?
I would actually prefer just "mix" but I'm sure you have already realized that Facebook is not exactly a shining beacon of grammar.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.