I guess you meant SUMIF. Don't think so, SUMIF takes only 3 arguments.
Regards,
KL


"Ray" wrote in message
...
KL,

Thanks for your useful suggestion. Is it possible to apply to countif
function as well?

Thanks,

Ray

"KL" wrote in message
...
=SUMPRODUCT(--(A1:A100="week1"),--(B1:B100=""),C1:C100)

or a little slower:

=SUMPRODUCT((A1:A100="week1")*(B1:B100="")*C1:C100 )

Regards,
KL


"Ray" wrote in message
...
I have three columns: a, b & c and need sum the figures on c if a = week1
and b = empty. Can someone suggest a formula to resolve this issue.

Thanks,

Ray