Add new "identifier" column with joined results from multiple rows for same customer ID

[AirBeast]

So embarrassed I can't figure this out...I've tried filters, IFs, concatenate, pivot tables...nothing seems to work.

Assume I have a two column spreadsheet:

Column A is "Customer ID"
Column B is "Customer Type"

This spreadsheet is tens of thousands of rows long. There are only two possible entries for "Customer Type": Apples or Bananas. Every row has one entry per Customer ID, but only one entry. I want to add a third column that helps me understand whether the customer has "Apples" or "Apples/Bananas". I will never have a situation where a customer has just "Bananas." Some customers have "Apples" for every row. Some have one or more instances of "Bananas". But every customer has at least one instance of "Apples."

Here's an example:

Customer ID Customer Type
1001 Apples
1001 Apples
1002 Apples
1002 Bananas
1003 Apples
1003 Apples
1003 Apples
1003 Bananas
1003 Apples

What I want is the third column called "Customer Preference" that reflects the following:

Customer ID Customer Type Customer Preference
1001 Apples Apples
1001 Apples Apples
1002 Apples Apples/Bananas
1002 Bananas Apples/Bananas
1003 Apples Apples/Bananas
1003 Apples Apples/Bananas
1003 Apples Apples/Bananas
1003 Bananas Apples/Bananas
1003 Apples Apples/Bananas

Thank you SO MUCH for your help.

[mlcb]

Try this formula in C2 copied down

="Apples"&IF(COUNTIFS(A:A,A2,B:B,"Bananas"),"/Bananas","")

Hope this helps

[AirBeast]

Thanks a ton! Worked perfectly!
Can I trouble to explain what the COUNTIFS parameters are doing? I'd really like to learn how to apply this to other data sets I have.

This was so helpful. Can't thank you enough!