On 1st July 2014, ND Limited issued 10,000 6% Debentures of Rs 150 each at par, the interest being payable half-yearly on 1st January and 1st July, According to the terms of the issue the debenture-holders had the option of getting the debentures converted into equity shares of Rs 100 each at a premium of Rs 50 each on 1st January, 2017. The company had the right to buy at any time its debentures in the open market for cancellation. On 1st May 2015 the company purchased 1,000 debentures at Rs 148 cum-interest and on 1st November 2016 it purchased 1,500 debentures at Rs 146 ex-interest; the debentures being cancelled immediately in both the cases. On 1st January, 2016 holders of 4,000 debentures exercised their option getting their debentures converted into equity shares. The company closed its books of account every year on 31st March. You are required to show journal entries for all the transactions relating to debentures during 2014-15, 2015-16 and 2016-17.