Final answer:
The car's average speed is 50 mph, calculated by dividing the total distance (150 miles) by the total time (3 hours).
Step-by-step explanation:
The question asks for the average speed of a car that covers a distance of 150 miles. To find the average speed, we first need to know the total time taken for the entire trip. We know from the question that the first half of the trip, which is 75 miles, is covered in 1.5 hours. Since the speed is constant, the second half of the trip will also take 1.5 hours, making the total time for the trip 3 hours. Now we can use the formula for average speed:
average speed = total distance / total time
In this case:
average speed = 150 miles / 3 hours = 50 mph
Therefore, the correct answer is (c) 50 mph.