I wonder to what extent there is anyone who could cope with the Oxford course but who could not breeze through A-level Further Maths. I entirely understand that the converse is false: there are people who are extremely good at exams but who simply couldn't cope with the Oxford course.
Almost all of those on the Cambridge maths course (which I'm taking to be similar) found A-level maths/further maths very easy. Of course, the admissions process selected for such people, but I think "finds A-level maths content very easy" is a prerequisite for the course.
Almost all of those on the Cambridge maths course (which I'm taking to be similar) found A-level maths/further maths very easy. Of course, the admissions process selected for such people, but I think "finds A-level maths content very easy" is a prerequisite for the course.