@tasmina:
With your maths marks, you should easily be able to handle MATH1151 even if you havent done 4u. The only thing you miss out on not doing 4u is integration techniques and complex numbers, 2 of the easier topics in 4u so you would be able to pick that up easily thru self study. So you should be able to cope with actuarial studies IF you are willing to put in the effort. Keeping a 80+ WAM in first year isnt too hard (in commerce at least, law is a different matter), but future years gets harder to cope with particularly for actuarial studies. So main question is whether you really want to do actuarial studies. If so, stick to it cos although you may lose the scholarship (prob not likely), the future rewards from an actuarial career outweighs the current benefits of the scholarship.
Btw, math1151 exempts quant A, so if you decide to drop actuarial studies to do finance, you dont have to do quant A.