From the following information, calculate Opening Trade Receivables and Closing Trade Receivables :
Trade Receivables Turnover Ratio - 4 times
Closing Trade Receivables were Rs 20,000 more than that in the beginning.
Cost of Revenue from operations - Rs 6,40,000.
Cash Revenue from operations \( \frac{1}{3} \)rd of Credit Revenue from operations
Gross Profit Ratio - 20%
Match List-I with List-II:
\[\begin{array}{|c|c|} \hline \text{List-I (Accounting ratio)} & \text{List-II (Type of ratio)} \\ \hline \text{(A) Current ratio} & \text{(I) Liquidity ratios} \\ \hline \text{(B) Stock turnover ratio} & \text{(II) Activity ratios} \\ \hline \text{(C) Debt Equity ratio} & \text{(III) Solvency ratios} \\ \hline \text{(D) Operating ratio} & \text{(IV) Profitability ratios} \\ \hline \end{array}\]
Choose the correct answer from the options given below:
Study the given molecular structure of double-stranded polynucleotide chain of DNA and answer the questions that follow. 
(a) How many phosphodiester bonds are present in the given double-stranded polynucleotide chain?
(b) How many base pairs are there in each helical turn of double helix structure of DNA? Also write the distance between a base pair in a helix.
(c) In addition to H-bonds, what confers additional stability to the helical structure of DNA?