=--ТЕКСТ((A1&":"&C1&":00")*24;"[чч]:мм:сс")*5500

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
Dim tt_&
tt_ = Cells(Rows.Count, 1).End(xlUp).Row
    If Target.Count > 1 Then Exit Sub
    If Not Intersect(Target, Range("A1:A" & tt_)) Is Nothing Then
        If Target.Cells.Value = "ïðèõîä" Then
            Target.Offset(0, 1).Resize(1, 2).ClearContents
        End If
    End If
    
End Sub