The double negation in terms two and three are there to convert True and
FALSE to 1 and 0, repespectivley
So we do not need them in the first term
=SUMPRODUCT(A1:A25,--(B1:B25="Y"),--(C1:C25="Y"))
For more details on SUMPRODUCT
http://www.xldynamic.com/source/xld.SUMPRODUCT.html
http://mcgimpsey.com/excel/formulae/doubleneg.html
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
www.stfx.ca/people/bliengme
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