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Problem 1. A caterer knows that in connection with the meals she has arranged to serve during the next n days, she will need r;> 0) fresh napkins on the jth day (j = 1,2,...n). Laundering normally takes p days - i.e. a soiled napkin sent for laundering immediately after use on the jth day is retunrned in time to be used again on the(; + p)th day. However, the laundry also has a higher cost service which returns the napkins in q