d = distance traveled by the car = 5/16 mile
t = time taken to travels the distance "d" = 1/4 min
R = rate at which car travels = ?
rate at which car travel is given as the ratio of distance traveled to the time taken to do so.
hence the rate of travel of car is given as
Rate = distance traveled/time taken
R = d/t
R = (5/16)/(1/4)
R = 5 x 4/(16 x 1)
R = 20/16
R = 1.25 miles per minute