Learning about different problem solving strategies and when to use them will give you a good start. Problem solving is a process. Most strategies provide steps that help you identify the problem and choose the best solution. There are two basic types of strategies: algorithmic and heuristic.
It should be 'No vacancies' (plural). Vacant means empty/free. Vacancy is the state of being empty, therefore 'no vacancies' = no empty rooms.
Updated December 25, 2016. Definition: Vacancy and Credit Loss in real estate investing is the amount of money or percentage of net operating income that is estimated to not be realized due to non-payment of rents and vacant units.