Column A1:A10 has a 0 or 1 in each cell, Column B1:B10 has numbers. I want
to be able to select the 0 (zero's) in Column A and AVERAGE only those
numbers at right in Column B.

I tried AVERAGE(IF(A1:A10=0,B1:B10) but got an average of all the numbers
in Column B, not just those at the right of 0.