ok,firstly,
JAE is joint-admission exercise. this one, the whole o level batch will be filling in 12 choices of courses/schools(if choosing JC). so, you better fill in 12 choices when given this to fill, you might be left school-less if you fill in only, say 6 courses.
SAE is special admission exercise. courses offered under SAE would usually require you to undergo a written test and an interview. before that, you must qualify with at least a B4 in english and at least c6 in humans( I THINK)
so, lets say you score b3 for english, but die die wanna go into mcm(np), then maybe you failed your sci OR math(maybe) and got relatively good grades in other subjs(MT,Humans), they would consider you and allow you to sit for the written exams.
MCM(np) was opened up to JAE, so now we have lots of students coming in with crazy scores. my batch, they accepted 100 through jae, 100 through sae. i seem to be able to go on and on about this.
and our friend is able to get 12 for l1r4 because maybe his sci grades are ommited(unless he got super duper great scores for the rest. mm. also possible)
but this is the Olevels(which would indirectly(or directly) affect what type career you'll have) you are talking about. my advice is do well for maths, sci one humans and English. it sounds like im asking for alot, but if you really put in effort, you can be able to achieve it.
my friend failed her science and was not given any school through JAE, lucky for her she got into MCM through SAE.. usually people who get into through SAE are the ones who are able to charm the pants off the interviewers.
nyeargh, if you want to know more. just pm me on msn or what la. im like writing an essay already man,
and i have no regrets at all 
