Public Sub Group()
Dim a$, b$, i&
' starting with A1 but you can change it below
With Range("A1")
a$ = .Value
b$ = .Offset(0, 1).Value
i = .Row + 1: j = .Column
End With
next_a$ = Cells(i, j).Value
next_b$ = Cells(i, j + 1).Value

While next_a$ < ""
Rows(i).Select
If ((a = next_a) And (b = next_b)) Then
Cells(i - 1, j + 2).Value = Cells(i - 1, j + 2).Value & "/" &
Cells(i, j + 2).Value
Rows(i).Delete
Else
a = next_a
b = next_b
i = i + 1
End If
next_a$ = Cells(i, j).Value
next_b$ = Cells(i, j + 1).Value
Wend
End Sub