the answer is 875 but i need proper working , i dont understand thanks

Question 4 On 1 July 20X3 Alpha Ltd acquired a 25% share of Beta Ltd. At that date the following assets had carrying amounts different to their fair values in Beta's books: Asset Carrying Fair value amount Inventories $12 000 $15 000 Machinery $24 000 $30 000 All inventories were sold to third parties by 30 June 20X4. On 1 July 20X3, the machinery had a remaining useful life of 3 years. The tax rate is 30%. The adjustment required to the Investment in Associate account at 30 June 20X4 in relation to the above assets is: Va. $875 Ob. $1250 O c. $3500 O d. $5000