To find the speed, you'll have to use the equation: s = d / t ; where s=speed, d=distance, and t=time
On her first run:
s = d / t
s = 400 meters / 4 mins
s = 100 meters/min
On her second run:
s = d / t
s = 400 meters / 6 mins
s = 66.66666 meters/min
To find the average of her speed, add both her speed/min and divide it by two:
100 meters/min + 66.66666 meters/min
= 166.66666 meters/min / 2
= 83.3333 meters/min
Jaslyn's average speed is 83.33 meters/min