Oh ok cool thanks i might just buy both for units 3 and 4 and just wondering what is the most effective way to study for biology sacs and exams cause i really dont know how to?
For SACs, you need to be able to study all the theory of the prac, but also think about the experiment, control variables, the importance of repeating experiments, etc, because they're typical qs on SACs. Also, because there are so many sacs, 10 in total, you must find the right balance between studying the theory & studying sac-specific. Often the theory coincides, but you must not disregard any other specific aspects of the sac that you must know.
For the exam, because there is no mid-year, you need to consistently read through unit 3 notes during term 3 to ensure all unit 3 info is consolidated. Otherwise, you'll forget the concepts & that is not what you want. As I've come to learn, it isn't so much the number of practice exams you do, but the skill you should acquire from doing prac exams should be to rectify errors & maximise the marks you obtain.
Best of luck

most importantly, enjoy the subject! It's amazing!