Lampost Manufacturing provides the following information:

To produce a unit of product:

Mixing department 4 minutes per unit

Molding department 7 minutes per unit

Casting department 9 minutes per unit

Finishing department 5 minutes per unit

There is a wait time of 5 minutes before the mixing department begins a batch, 5 minutes between the mixing and molding departments, a move and pre-wait between molding and casting of 10 minutes, and a move and pre-wait between the casting and finishing departments of 8 minutes.

Required:

How long does it take to produce a batch of 20 units under a traditional manufacturing approach? (be sure to show all work)