Answer: Sally
If Harry's negligent act injures Sally, and Susan, while attempting to come to Sally's aid breaks her arm in the process then, Harry is liable for the harm to Sally.
Explanation:
As a mathematical expression, we can say the action of Harry H, is directly proportional to the injury to Sally S; while the mistake of Susan N is directly proportional to injury to Sally S.
So, if H = S and N = S, it is safe to say
H = N = S.
Thus, Harry negligence create room for Susan mistake, which eventually harmed Sally.
When population don't change very much over time, the ecosystem is in equilibrium.
