In theory, yes, you can still do really well and get 48 or above. What counts is the ranking and then your end of year exam mark, so basically if you use the remaining SACs to pull up your ranking, then a 48 is definitely still possible when combined with a great exam score. So rest assured because the numbers or stats or whatever say it can happen (but don't actually rest)!
In practice, though, that'll probably mean a lot of work and improvement required on your part. It may sound simple to say that you'll just do well on the rest of the SACs and the exam, but you've really gotta think about how you'll do it, and start working on it. You said the main problem is the way you answer questions, so just do some practices and show your teacher (and us too, we're all willing to help!) and keep getting feedback and follow it until your answers are in the 'right manner'

It'll probably take a bit of time, but if the way you answer questions is your main problem, then fixing that should hopefully have you seeing much better results for your remaining SACs and the exam, since it's just one thing to work on overall, rather than if you had heaps of issues with content or different little things.
And yeah dude, select entry cohort can make things seem A LOT worse than they are with SAC scores and then you usually get a nice surprise after the exam
