PA $7-10($Algo$)$ Aquatica makes underwater camera housings...

Aquatica makes underwater camera housings for divers. The process begins with a solid rectangular block of aluminum that is used to make a single housing. A Computer Numerically Controlled $($CNC$)$ machine drills into the block to make the metal "frame" of the housing. Each block requires $15$ minutes of drilling. The frame is then chemically treated in a series of baths. There is ample capacity in the treating stage. Finally, a worker must manually attach the various buttons and components to the metal housing. This assembly takes $120$ minutes per housing per worker and Aquatica has $6$ workers trained to do this task. The CNC machine requires a $30-$minute setup time before the production of a batch can begin.