he Fine Crate Company owns several machines which cut wooden planks for building storage pallets, automatically loading the planks into rolling bins for transportation and handling. Each bin holds 200 planks and a machine can cut and load one bin in an hour, which Fine Crate Company uses planks at a rate of 1000 planks an hour. If the Fine Crate Company were to use a kanban loop to control the filling of the rolling bins, attaching one kanban card to each bin, how many cards should be used to govern this production, assuming a policy variable (safety factor) of 20%?