The following activities and times (in minutes) were recorded for a mold operator:

- removes molded piece from die 0.6

- walks 10 ft to a workbench 0.2

- boxes widget and places on conveyor 1.0

- walks back to molder 0.2

- blows out dirt from mold 0.4

- sprays oil into mold, pushes "GO" 0.2

- mold cycles automatically for 3.0

The cycle then repeats itself. The operator is paid $10.00/hr and it costs $15.00/hr to run the molder. What is the optimum number machines that can be assigned to the operator to produce the widgets at lowest cost? Draw a worker-machine chart.