Help on grades!

Hey,

I've received an offer for a foundation year and the requirements are a CDD and currently I'm on a BDE.

The E is in Psychology and on my grade sheet by the school my UMS for Unit 1 is 46 and for Unit 2 is 36 and an overall mark of 95 raw score.

The question is, what would i be required to get in Unit 3 and Unit 4 in order to bring this up to 50 UMS?

Also, for Psychology, the grade boundaries are not in line with the UMS. for example, 50 UMS (50%) is not 50% of the paper mark, it is normally 32/70, is this correct as 50/100 UMS still or below even if the boundaries say 32 is a D?

Thnaks.