Question 3. A group of n firms uses a common resource (a river or a forest, for example) to produce output. As more of the resource is used, any given firm can produce less output. Denote by T;, the amount of the resource used by firm i (i = 1, ..., n). Assume specifically that firm 's output is a;(1 -(21 + .. . + In)) if x1+ 2 + . ..+ n