Using IF THEN ELSE in Excel 2007

I need to write a formula for the column I in an excel worksheet.

For I4:

IF(A4=A3 & A3=A2) then (I4= (220-(G2+G3+G4))/200) Else (I4=((220-G4)/220))

Similarly,
For I5:

IF(A5=A4 & A4=A3& A3=A2) then (I5= (220-(G2+G3+G4+G5))/200) Else (I5=((220-G5)/220))

and so on...

Could you please provide the correct syntax to use this logic?

Daymaker