i run a spreadsheet that calculates commision for sales people

Column I is a product list
Column P is total sales value

Column Z is the name of a sales person who shares the commission with the
main "owner" of the worksheet. (Each worksheet is for one sales person - but
commission can be shared)

some products share the commission 50-50 between the sheet owner and the
person in Column Z
other products share 70-30

how do i write an IF statement that says something like:
IF(I3="Business" and Z3="Mark", p3*.5, but if I3="Person" and Z3="mark"
P3*.7)

I hope the question is clear!!

TIA