How to find the most common item number

[mljohn]

I don't even know how to set this up.

I have various suppliers lists who have several item numbers for the same item.
They are printer cartridges and for the same printer cartridge, there may be several part numbers. So far I have found up to 11 part numbers for the same item.
I want to find which of the part numbers is the most common amongst the various suppliers.

Right now I have all of the supplier's info in one sheet. Col A is the Suppliers name, Col B is the Brand of the printer cartridge, Col C is the item number or numbers.
However, maybe it would be better to separate the suppliers into its own sheet.

Each item number is separated by a comma and space. For example: "Series 21, 22, 23, 24, T093N, T091N, T105N, T109N, 3305253, 3305255, 3305887"

Can this be done and if so how?

Thanks

 

[mljohn]

I want to find which number is the common number in all the suppliers

 

[mljohn]

Is this not possible?