It isn’t – it is 0.40. There is a typing error in the answer in the notes, but the final answer is correct at 16.10%. Did you not calculate it yourself first? 🙂
However you should not be using the notes if you are not watching the lectures, and in the lectures I use the correct figures.
The notes are only lecture notes and it is in the lectures that I explain and expand on the notes, and work through all of the examples. If you are not watching the lectures for any reason then you need to study from a Study Text from one of the ACCA approved publishers if you are to pass the exam.