Answer:
v = 3.75 mph
Explanation:
Constant speed motion
An object travels at a constant speed if the ratio of the distance traveled by the time taken is constant.
Expressed in a simple equation, we have:

Where
v = Speed of the object
d = Distance traveled
t = Time taken to travel d.
Sam walks from home to school for a distance of d=0.75 miles in t=12 minutes. To calculate the speed, we need to convert the time to hours.
t=12/60 = 0.2 hours. Now compute the speed:

v = 3.75 mph