Remember the fourth sentence of the introduction - if you don't know which one then guess! The introduction also says that some personal research may be permitted. So, if you think one of the answers is "Leningrad Symphony" [it isn't] then I don't necessarily rule out using Google to find out who wrote the Leningrad Symphony to see if it's a likely contender (though your personal ethics might, I don't know). Similarly, if you think one of the tunes may be on your CD of Rutter's collected works [it isn't] then listening to the CD to find out isn't out of the question.
Another hint to one of the questions may possibly be found here.