On $1$ July $2019,$ Biru Bhd acquired a patent for its new product at a cost of RM$2,000,000.$ The estimated useful life of the patent is ten years. The management of the company, however, was not able to determine reliably the pattern in which the patent's economic benefits are consumed. On $31$ December $2020,$ the company revalued the patent to market value of RM$2,600,000.$ Due to significant decline in demand of the product, the company revalued the patent downwards to RM$1,400,000$ on $31$ December $2021.$

Meanwhile, on $1$ January $2022,$ as part of Biru Bhd business expansion strategies it acquired all of the ordinary shares of Wau Sdn Bhd$.$ Wau Sdn Bhd has become a division $($cash generating unit$)$ of Biru Bhd$.$ It was determined at the acquisition date that the different between the fair value of the identifiable net assets of Wau division with the cash consideration paid was RM$700,000.$ After $10$ months of operations, Wau experienced operating losses. In addition, it is expected that Wau division will generate substantial losses for the foreseeable future. At $31$ December $2022,$ carrying amount of Wau's division net assets is RM$1,760,000.$ Meanwhile, its recoverable amount on that date as determined by professional appraisers is RM$1,450,000.$ Biru Bhd$\text{'}$s year end is $31$ December. The company uses revaluation model to recognise the patent.

Required:

a$.$ Identify method of amortisation that should be used to amortise the patent $($justify your answer$).$ Prepare journal entries necessary to record the subsequent measurement in $2019$ and $2020$ and increase in market $($fair$)$ value of the patent in $2020.$

$(6$ marks$)$

b$.$ Prepare journal entries necessary to record amortisation expense, gradual realisation of the revaluation surplus, and decrease in market $($fair$)$ value of the patent in $2021.$

$(6$ marks$)$

c$.$ Determine the impairment loss $($if any$)$ of Wau division on $31$ December $2022$ and prepare the journal entry to record the impairment loss.

$(2$ marks$)$

d$.$ Assume that goodwill arises from the acquisition of Wau division is less than the amount of the impairment loss computed in $($c$).$ How should the impairment loss being allocated?