The amount of cash to be kept by a bank is at least 50,000 TL, the variance of daily cash flows is 20,000 TL, and the fixed transaction cost is 3,500 TL.

a) If the annual interest rate is 20%, what is the cash balance and upper limit targeted according to the Miller and Orr model?

b) If the bank's cash level reaches the upper limit you calculated, how much and what kind of transaction should the bank take?