formula problem

[kyoko]

i really need help for this one:
A B C
oct. 27 -50% cover
oct. 27 -50% not cover
oct. 27 50% cover
oct. 28 100% cover
oct. 28 -150% cover
oct. 29 -50% cover

i would like to return a value where i only need the number of "cover" from
oct. 27 to oct. 29 that is under -50%...is there any formula so that i can
easily get the total number of "cover" at -50%

 

[bapeltzer]

=sumproduct(--($B$1:$B$6="-50%"),--($C$1:$C$6="cover"))
Used this way, the sumproduct is like a multi-criteria countif (if you're
using Excel 2007, you might check out the countifs function).
I'm guessing that the -50% in your data is text; if not, change the "-50%"
in the formula to -0.5.