Depends on the time you put toward it, you can easily do HUF, MET, NAV and LAW in a week, may want a little extra for the others as they tended to be the more 'in depth' exams, but 2 weeks is more than enough for them. If your good at certain subjects you could even study them over a few days, one bloke i know is good with maths and did performance over a weekend!