$(3\mathrm{.}3)$ A batch production operation has a machine setup time of $3\mathrm{.}0hr$ and a processing time of $1\mathrm{.}60$min per cycle. Two parts are produced each cycle. No tool handling time is included in the cycle. Part handling time each cycle is $45sec.$ It consists of the worker obtaining two starting work units from a parts tray, loading them into the machine, and then after processing, unloading the completed units and placing them into the same tray. Each tray holds $24$ work units. When all of the starting work units have been replaced with completed units, the tray of completed parts is moved aside and a new tray of starting parts is moved into position at the machine. This irregular work element takes $3\mathrm{.}0$min. Batch quantity is $2,400$ units. Determine $($a$)$ average cycle time, $($b$)$ time to complete the batch, and $($c$)$ average production rate.

$3\mathrm{.}4$ A flow$-$line mass production operation consists of eight manual workstations. Work units