The following journal entry appears in the books of X Co. Ltd.
\[\text{Bank A/c Dr. 4,75,000} \\ \text{Loss on Issue of Debentures A/c Dr. 75,000} \\ \text{To 12\% Debentures A/c 5,00,000} \\ \text{To Premium on Redemption of Debenture A/c 50,000} \]
In this case, the debentures have been issued at a discount of 5%. What is the rate of premium on redemption of debentures?
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?