According to the textbook context, when a partner retires and there is no specific information about how the remaining partners will acquire the retiring partner's share, it is assumed that they acquire it in their old profit sharing ratio. Consequently, the new profit sharing ratio among the continuing partners remains the same as their old ratio. The context explicitly states: 'there is no need to compute the new profit sharing ratio among them, as it will be same as the old profit sharing ratio among them.'