CountIfS Inter-Column Date Evaluation

[ChasD]

Hi - Have poured through much content on COUNTIFS but can't seem to find a solution to my variant...

I have several columns that record dates for various events:

A B C
1/1/2010 2/1/2010 3/1/2010

I want to count B if it is non-blank AND if C is blank AND if A<=B

Formula thus far:
=COUNTIFS(B1:B50,"<>",C1:C50,"",A1:A50, "<="&??????)

????? - is what I can't figure out. I have tried:

A1:A50, "<="&B1:B50 (results in 0 count)
A1:A50 "<="&B1 (works, but only evaluates B1... i.e. not relative as it goes down the range of B1:B50)

HELP! What am I corn-fusing here...?

 

[AlphaFrog]

Try this...
=SUMPRODUCT((B1:B50<>"")*(C1:C50="")*(A1:A50<=B1:B50))

Or this...
=SUMPRODUCT(NOT(ISBLANK(B1:B50))*ISBLANK(C1:C50)*(A1:A50<=B1:B50))

 

[ChasD]

Worked great AlphaFrog! Thanks.