Answer: Two days
Explanation: Installing hardwood floors in a 500 square feet space, which is essentially one room without stairs, can typically be done in two days. This timeframe can vary based on factors such as the condition of the subfloor, the type of hardwood flooring, and the efficiency of the installation crew. It's also important to consider any necessary preparation time, such as removing existing flooring or preparing the subfloor, as well as time for finishing and clean-up after the installation.