Hi all, thank you in advance for your help ,and help in past.

I am trying to count the number of "yes" in column C if Column A has a
unique value, see below:

| A | B | C |
10 N/A yes
10 N/A yes
11 N/A no
11 N/A no
12 N/A yes
13 N/A no
13 N/A no
13 N/A no

Basically this is part of verifying invoices, A being the invoice
number, each invoice can have mnore then 1 entry thus there being two
10's.

Column C represtent weather that invoice entry has been a success or
not.

What i need to know is the number of invoices that were a success
(Column c)

So.... in the example above the formula would return 2, as invoice 10
and 12 were a success but not he others.

I hope i have made sense, i have been trying to figure this out for a
few days noe, i have got as far as working out the number of unique
entriers in column a by useing array formulas, but get stuck.

Hope someone can help

Many Thanks