I call bogus on Intel's online quiz. It's not an attempt to determine if people are good at spotting fishing attempts, but rather a marketing tool to convince people that they are not good at it and must rely on McAfee (owned by Intel) to protect themselves.
For some example emails only a small fraction of the email is shown, and if you can't see the sender or the receiver or see links in the email, then it's not possible to determine if something is phishing or not.
The only way to get all questions right is to be a good guesser.
It's one of two reasons you cannot determine (except by guessing) if those emails are phishing.
Of course, in the real world, you probably won't be looking though someone else's e-mail. Instead, you be looking though your own, which means you'll know what e-mails are bad based on whether or not you were expecting said e-mails.
And that's the other reason why it's not possible to determine whether some of those emails are phishing or not.