Answer : The Elena’s running speed is, 5 mile/hour
Step-by-step explanation :
Speed : It is defined as the rate at which an object moves with respect to time.
To calculate the time taken for the given speed, we use the equation:

where,
s = speed = ?
d = distance traveled =

t = time taken =

Putting values in above equation, we get:

Hence, the Elena’s running speed is, 5 mile/hour