Costa Co. uses three identical pieces of machinery in its factory. The cash price of these machines is each and their estimated lives four years. These were all brought into use on the same date by the following means: (a) machine 1 was rented from Brava Co. at a cost of  per month payable in advance and terminable at any time by either party; (b) machine 2 was rented from Blanca Co. at a cost of eight half-yearly payments in advance at  (c) machine 3 was rented from Sol Co. at a cost of six half-yearly payments in advance at Are the above machines rented by operating lease or by finance lease according to the current IASB rules?