calculated value: combine runtime function

HI,

one more question: is it possible to combine 2 or more runtime function ?

I need more than one If query, e.g. the average field sholuld be filled differently:

If(Gerätetyp=='BP',10) or  If(Gerätetyp=='FP',20) or If(Gerätetyp=='MP',30).

Is it possible and how can I do this?

Regards

Andrea