$2.$ A consulting firm is trying to determine how to minimize the costs associated with purchasing paper. Paper is consumed at the rate of $30$ reams per day. Each time an order is placed an ordering cost RM$100$ is incurred and the holding cost per ream per day is $1\%$ of the unit purchase cost. Suppose no shortage is allowed and that the purchasing cost per ream is RM$12$ for any quantity not exceeding $300$ reams and RM$10$ otherwise. Determine the optimal inventory policy, given a $15$ days lead time.