Part of the process of preparing a company's statement of cash flows is the calculation of cash inflow from operating activities.Which of the following statements about that calculation (using the indirect method) are correct?1Loss on sale of operating non-current assets should be deducted from net profit before taxation.2Increase in inventory should be deducted from operating profits.3Increase in payables should be added to operating profits.4Depreciation charges should be added to net profit before taxation.