Final answer:
The speed limit on non-posted rural roads can vary, but a common speed limit is 55 miles per hour.
Step-by-step explanation:
The speed limit on non-posted rural roads can vary depending on the jurisdiction. In general, it is advisable to drive at a speed that is safe and reasonable for the road conditions, taking into account factors such as visibility, traffic, and weather conditions. A common speed limit on non-posted rural roads is 55 miles per hour, but it's important to note that this may differ in different areas.