SQA MCA Engineering Management Exams UK General/Motor

Dears Sirs / Madams, I really would like to know your best advice on how to crack the SQA MCA Engineering Management Exams UK General and Motor, I'm really having a hard time with this interlock system, pass one but failing the other and then I have to give both again even after passing one, we should be allowed to resit only for the failed paper. It's really getting frustrating. Any advice will help. Many Thanks.