CarpetQuote.cls

Option Explicit

Public Function Quote(ByRef room As Room, ByRef carpet As Carpet) As Double
    Quote = Price(carpet, Area(room))
End Function

Public Function Area(ByRef room As Room)
    Area = room.Width * room.Length
End Function

Public Function Price(ByRef carpet As Carpet, ByVal area As Double)
    If carpet.RoundUp Then
        area = Ceiling(area)
    End If
    
    Price = carpet.PricePerSqMtr * area
End Function