Final answer:
Sam's walking speed to school is calculated by dividing the distance (0.75 miles) by the time in hours (0.2 hours), resulting in a walking speed of 3.75 mph.
Step-by-step explanation:
The question requires calculating Sam's walking speed from his home to school. To do this, we first need to convert the time spent walking from minutes to hours since speed is typically given in miles per hour (mph). There are 60 minutes in one hour, so 12 minutes is equal to 12 / 60 = 0.2 hours. Speed is calculated by dividing the distance traveled by the time taken to travel that distance. Therefore, Sam's walking speed is 0.75 miles / 0.2 hours = 3.75 mph. The correct answer is B. 3.75 mph.