A cаr wаsh is cоnsidering а twо-part tariff/pricing plan. Under this plan, custоmers would pay a fixed monthly membership fee plus a price for each car wash.Each customer has demand:P = 20 - Q(or Q = 20 - P)where P is the price per car wash and Q is the number of car washes per month. The marginal cost of providing one more car wash is $4. If all customers have identical demand, what are the optimal per-wash price and fixed monthly membership fee? Current Answer Choice: Per-visit price = $4; fixed fee = $128