I'm looking for the right formula. I have two columns of data. Column A
lists countries where activities are taking place, column B categorizes the
country as one of five types. How can I total the number of different
countries that fall under each category of country?

For example, Australia might appear 6 times in Column A but it should not
count as six instances of the country type associated with it. If should
only count as one instance of that country type. Assuming for a moment that
Oman is given the same country category as Australia, it should also count as
one instance of that country type, regardless of how many times Oman appears
in Column A.

TIA . . .