A ratio answers a specific question using consistently defined inputs. The current ratio compares current assets with current liabilities. The quick ratio excludes inventory and prepayments because they are less immediately available to settle debt. A ratio needs context such as the business model, prior periods and any definition in a loan agreement; a number alone is not a verdict.
Turnover measures often use average balances because income statement activity covers a period while the balance sheet captures a date. Use average receivables for collection days and average inventory for inventory days when both endpoints are available. Keep days and annual rates consistent. If a denominator is zero, explain that the ratio is undefined rather than dividing by zero.