Why do you multiply 1.15 instead of divide?

DvD Limited's April beginning inventory and April purchases of inventory are as follows (shown net of GST and 2% discount): Beginning inventory Purchase on 6 April Purchase return on 10 April Purchase on 25 April Quantity Unit Cost 200 $196 450 $196 (100) $196 300 $196 Total Cost $39,200 $88,200 ($19,600) $58,800 DvD Limited had two sales in the month of April (selling prices include GST): On 3 April, 150 units were sold, on credit, for a selling price of $690 per unit. On 28 April, 300 units were sold, on credit, for a selling price of $736 per unit. b) After the 450 unit purchase of 6 April and before payment, 100 units were returned to Alex Limited on 10 April. Reproduce the journal entry that had been correctly prepared by DvD Limited for the 10 April purchase return. (2 marks) Cr Dr 23,000 Account Name Accounts Payable Inventory GST Clearing/Payable (purchase return, payable 196+0.98 x 1.15 x 100) 20,000 3,000 Marks 0.5 AP dr 0.5 Inv cr 20,000 0.5 GST cr 0.5 GST calc correctly (0.15 x dr/cr value giving dr/cr value)