How do I SUMIF with two criteria in two different columns?

[Tina Winter]

Good afternoon everyone. I have a task management table in which three of
the many columns indicate the week (Column "A") the work should be done, the
person (Column "B") who should do it and the time (Column "C") it will take
to get it done. I need to total each person's time based on who does it and
in what week. In other words, I need the formula to sum the time only if
the person (B)= X and the week (A)=Z. I have tried everything I can think
of, but I just can't make it work.

Any advice on this would be greatly appreciated. Thank you! Tina

 

[LanceB]

Try
=sumproduct((b1:b100=x)*(a1:100=z))

Lance