Apply mathematical skills around cost structures and appropriate equations to answer the following, inclusive of all asaociated workings to maximise marks: Opening Inventory + Purchases - Closing Inventory = Cost of Sales (CoS) Mark up cogt structure example with example of Margin cost atructure a) A fire on 31st October destroyed some of a company's inventory and its invantory rerords The following information is available: Based on this information, what is the value of the inventory lost? (3 marks) b) What are the definitions and business uses of calculating mark-up and margin? Please use Harvard when citing any sources. (4 marks) c) Calculate mark-up (in percentage to 2 decimal places) (1 mark) d) Calculate the margin as a % to 1 decimal places (1 mark) e) What is the operating profit margin percentage if the admin cost is reduced by 50% ? Show this to 2 decimal place (2 marks) f) Define the following and provide respective examples with numeric calculations where possible. Please use academic sources: Trade discount ( 1 mark for definition and 1 for example) Simple interest ( 1 mark for definition and 1 for example) Compound interest ( 1 mark for definition and 1 for example) (6 marks)