On $1$ January $2020,$ A Ltd acquired all the issued shares in B Ltd$.$ At that date, the plant of B Ltd had a fair value of $$20000$ more than its carrying amount and an estimated useful life of $9$ years. B Ltd depreciates the plant on a straight$-$line basis. The plant was sold during the year ended on $30$ June $2021.$ The business combination valuation consolidation adjustment against plant in relation to the transaction as at $30$ June $2021$ will be: $($Solution should be $$...)$