Disposal before purchase date

Hello Jilly , In the following question the disposal date is before the purchase within 30 days matching how can we account for the the cost of that when it was happening after the disposal date What's the logic behand it, Thanks. Question Hermione had the following acquisitions in Hogwarts Ltd. 10th June 12 Purchased 3,000 shares for £15,000 9th June 14 Purchased 7,000 shares for £32,000 23rd Dec 23 Purchased 1,000 shares for £5,000 5th Dec 23 Sold 5,000 shares for £30,000 Calculate the capital gain that will arise on this disposal. £6,200 £7,000 Answer FIRST MATCH – same day acquisition SECOND MATCH – 30 days following disposal acquisition THIRD MATCH – share pool None. 23/12/2023 – 1,000 shares for £5,000. 4,000 shares needed from share pool. Share pool: Description Number Cost 10/06/2012 purchase 3,000 £15,000 9/06/2014 purchase 7,000 £32,000 Total 10,000 shares £47,000 Disposal from share pool (4,000 shares) (4,000/10,000) * £47,000 = (£18,800) Remaining in share pool 6,000 shares £28,200 Specially note how the cost of the shares from the share pool is calculated. (No. of shares to be disposed from pool/Total shares in pool) * Total cost in pool = Average cost that we apply to our disposal. Calculating capital gain: Disposal proceeds £30,000 Acquisition cost: 23/12/23 (£5,000) Share pool (£18,800) Capital gain £6,200