Try a macro like this:
Sub test()
Dim i As Long
For i = Cells(Rows.Count, "C").End(xlUp).Row To 2 Step -1
If Cells(i, "C") = Cells(i - 1, "C") Then
Cells(i - 1, "A") = Cells(i - 1, "A") & " / " & Cells(i - 1, "A")
Rows(i).Delete
End If
Next i
End Sub
PS. Posting sample workbook not only picture makes answering easier - ona can check how the proposition works.
For instance - if numbers in A are short - excel could try to "help you and change for instance "11 / 12" to date. But no file -> no testing.
Bookmarks