Hi. Welcome to PPRuNe.
The UK CAA PPL Exams are in a mess at the moment. Lots of stuff not matching the textbooks, whatever series of books you buy.
The best thing you can do right now, is spend about £12 and get the McPhee EASA PPL Exam app for your phone, or tablet. All the current questions for all the PPL Exams, including the IMC Rating are on there.
Keep doing the questions on there until you are consistently getting 90%+ all the time, and no new questions come up each time you start a new set, and you will pass without any problems.
I know it sounds like cheating, but until the CAA get their act together, and sort out the Exams, that's the best way of being sure to pass.
MJ
