write a formula in Excel : I am using google sheets and I am trying to column A value in Column C When If Column B Value Duplicate,

 

         Column A    Column B           Column C
      1    1247       Santa Fe          1250/1150
      2    1250       Santa Fe          1247/1150
      3    1258       North Shore       1354
      4    1341       Hogan             1255
      6    1255       Hogan             1341
      5    1354       North Shore       1258/1354
      6    1150       Santa Fe          1247/1250

Here, Column C need multiple values of A of a duplicate of column B.