haha it would really help to ace maths coz it scales so well
but based on the uai calculators (which can be dodgy coz they're based on old data) its saying you roughly need
eng: 88/100
eng ext: 45/50
eng ext 2: 46/50
maths ext: 80/100
maths ext 2: 60/100
business: 90/100
eco:90/100
depending on which ones you would do better and worse in you could swap them around a bit but thats a rough estimate.. and that would give around a 96