I have 2 columns of data, A1:A10 has just numbers eg 123, 456 etc, B1:B10 has
a combination of letters and numbers eg ABC123, DEF456 etc. The data is not
continous within each column (ie there are blank rows within each range).

I need a formula for each range which will count the number of unique values
within each column. I have tried to find solution in similar Q&As but can't
seem to find a solution which will disregard the empty cells and not return a
#DIV/0! result.

Any help would be great. Thanks.
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Regards
Matt