The trade payable turnover ratio is a financial tool used to measure how frequently a company pays its creditors over a given period. It is used to determine the efficiency of a company's payment system and how effectively it uses its credit.

Formula for calculating Trade Payable Turnover Ratio:

Trade Payable Turnover Ratio = Net Credit Purchases / Average Trade Payables

Where Net Credit Purchases = Net Purchase - Cash Purchase - Purchase Return

Steps to calculate Trade Payable Turnover Ratio:

1. Calculate Net Credit Purchases
- Net Purchase = Rs. 10,00,000
- Cash Purchase = Rs. 1,00,000
- Purchase Return = Rs. 50,000
- Net Credit Purchases = Rs. 8,50,000

2. Calculate Average Trade Payables
- Average Trade Payables = (Closing Creditors + Closing Bills Payable) / 2
- Average Trade Payables = (Rs. 80,000 + Rs. 10,000) / 2
- Average Trade Payables = Rs. 45,000

3. Calculate Trade Payable Turnover Ratio
- Trade Payable Turnover Ratio = Net Credit Purchases / Average Trade Payables
- Trade Payable Turnover Ratio = Rs. 8,50,000 / Rs. 45,000
- Trade Payable Turnover Ratio = 18.89

Interpretation:
The trade payable turnover ratio of 18.89 means that the company pays its creditors approximately 19 times a year. This indicates that the company has a good payment system in place and is effectively using its credit. However, it is important to note that a high turnover ratio may also indicate that the company is taking advantage of its credit terms and paying its creditors too quickly, which may affect its cash flow in the long run.