1. The problem states that Marc’s family plans to drive a total distance of 150 miles at an average speed of 30 miles per hour. 2. Marc creates the expression $$150 - 30h$$ where $h$ represents the number of hours driven. 3. To understand what this expression calculates, recall the formula for distance traveled: $$\text{Distance} = \text{Speed} \times \text{Time}$$. 4. Here, $30h$ represents the distance traveled after $h$ hours because speed is 30 miles per hour. 5. The expression $$150 - 30h$$ subtracts the distance traveled from the total distance of 150 miles. 6. Therefore, $$150 - 30h$$ calculates the distance remaining after driving for $h$ hours. 7. The correct interpretation is: **the distance remaining after $h$ hours of driving**. Final answer: Marc’s expression calculates the distance remaining after $h$ hours of driving.