The cash management problem as a part of working capital management has been extensively studied. By and large the articles surveyed lacked consideration of long-term assets and the proper tax treatment of them. Recognizing that investment activities - long-term as well as short-term generate cash inflows, leads one to conclude that these investments should be included in the cash management problem. The liquidity of long term investments is an integral part of the cash management problem. This paper formulated a cash management model which incorporate the effect of long term investments and their liquidity on cash holdings. Although all of the models formulated could be solved using mathematical programing techniques, the mere size of the problem in terms of the number of variables and constraints leads one to seek other methods. For this reason rules were developed using the Kuhn-Tucker conditions thereby substaintially avoiding the programming calculations or at least easing them significantly.