Try this:

=SUMPRODUCT((C1:C20="X")*A1:B20)

--
HTH,

RD
==============================================
Please keep all correspondence within the Group, so all may benefit!
==============================================


"Mr. Jan Park" wrote in message
...
I have a 3 column table with 20 rows. The first two columns contain
travel
expense data. The cells in the third column are blank exept for whichever
cell I enter an "x" in. Please let me what formula or worksheet function
do
I use to calculate the travel expenses based on the data in the first two
columns that correspond to the row of the cell with an "x" in the third
column?

Thank You!