At the beginning of 2022, Metatec Incorporated acquired Ellison Technology Corporation for $600 million. In addition to cash, receivables, and inventory, the following assets and their fair values were also acquired:

Plant and equipment (depreciable assets)	$ 150	million
Patent	40	million
Goodwill	100	million

The plant and equipment are depreciated over a 10-year useful life on a straight-line basis. There is no estimated residual value. The patent is estimated to have a five-year useful life, no residual value, and is amortized using the straight-line method.

At the end of 2024, a change in business climate indicated to management that the assets of Ellison might be impaired. The following amounts have been determined:

Plant and equipment:
Undiscounted sum of future cash flows	$ 80	million
Fair value	60	million
Patent:
Undiscounted sum of future cash flows	$ 20	million
Fair value	13	million
Goodwill:
Fair value of Ellison Technology Corporation	$ 450	million
Book value of Ellisons net assets (excluding goodwill)	370	million
Book value of Ellisons net assets (including goodwill)	470	million*Footnote asterisk

^{*Footnote asterisk}After first recording any impairment losses on plant and equipment and the patent.

Required:

1. Compute the book value of the plant and equipment and patent at the end of 2024.
2. When should the plant and equipment and the patent be tested for impairment?
3. When should goodwill be tested for impairment?
4. Determine the amount of any impairment loss to be recorded, if any, for the three assets.