I have a spreadsheet that I would like to count the number of occurrences of
a particular value in one column that also have a particular value in another.

For instance, I want the number of times the value in column B = Yes when
the value in column C = 0.

I've tried using COUNTIF and SUMIF, but they both give me the result of the
two arguments added together as opposed to how many contain both values.

I would certainly appreciate any ideas.

Thanks.