Goodwill calculation issue

Dear Sir In the below question we calculate the Goodwill to be 0 What clues/calculations lead to this conclusion? I think they are: -No 'Opening' retained earnings (company was bought when created therefore nothing earned) -No 'Fair value of NCI at Acquisition' I have an idea about which I am less confident: -75% of Share Capital (at 20000) is 15000. So we paid 15000 for 15000 worth of company. Thus no goodwill do we calculate goodwill to be 0 as a result of ALL of these assumptions or a subset ? thanks in advance for your help regards P acquired 75% of the share capital of S on its incorporation. The Statements of Financial Position of the two entities as at 31 December 2010 are as follows: P S Non-current assets 50,000 25,000 Investment in S, at cost 15,000 Inventory 13,000 7,000 Other current assets 10,000 6,000 88,000 38,000 Share capital - $1 shares 45,000 20,000 Retained earnings 30,000 15,000 Current liabilities 13,000 3,000 88,000 38,000