Is this a job for SUMPRODUCT? Or is it easier?

[Bob Phillips]

[vba]=SUMPRODUCT((ISNUMBER(Y!$1:$3))*(Y!$1:$3<=Z!A1)*(X!$B$1:$B$3="T"))[/vba]

such that instead of = "T"

it could be

="C" OR ="K"

with the 1st two conditions still the same.

=SUMPRODUCT((ISNUMBER(Y!$1:$3))*(Y!$1:$3<=Z!A1)*(ISNUMBER(MATCH(X!$B$1:$B$3 ,{"C","K"},0))))

And while I am here, I would need another one such that instead of

= "T"

it must be

="C" AND ="K"

it can't be C and K, if it is C it is NOT K and vice versa.