A machine manufactures spare parts at the rate of 20, 000 per month. A second machine uses those spare parts at the rate 50 00 per month and remainder put into stock. It cost ₦100, 000 to set up the machine the company establish their stock hold costs 20% per annum of the average stock value each parts costs ₦250 to make. Required What batch size should be produced on the first machine and what frequency.