First, find the total of the distance she went through
distance = 4 × the perimeter
distance = 4 × 1/2
distance = 2
The total of the distance is 2 miles
Second, calculate the speed
speed = distance/time
speed = 2/50
speed = 4/100
speed = 0.04 miles/minute
Kristin's speed is 0.04 miles/minute