How to record this intra-group transaction and why?(Topic in financial accounting, consolidation worksheet)

On 1 January 2018, Son Ltd acquired furniture for $70,000 from Parent Ltd. The furniture had originally cost Parent Ltd $100,000 and had a carrying amount at the time of sale of $80,000. The sale was made on credit and, at 30 June 2018, $30,000 was outstanding. At 30 June 2019, $10,000 was still not paid and outstanding. Both entities apply depreciation on a straight-line basis. At 1 January 2018, the furniture had a further five years of useful life, with zero residual value.