The JC curriculum requires all students whatever JC they are in to offer a contrasting subject. Therefore if you are in the science faculty you would have to offer a contrasting subject from the arts or humanities. Similarly, if you are in the arts faculty you would have to offer either a science or mathematics subject. This provides you with a broad base of learning and will prepare you more effectively for the multi-disciplinary approaches that are being taken in university education. Check out the subject combinations offered by SAJC here.