Pc tulsian amalgamation group 2 problem help.

Hello all, in the below problem while calculating the net assets for equity shareholders- Investments in Debentures for both the companies is taken as Rs.16,000....Please tell me how the amount of Rs. 16000 is arrived at??

Additional Information:

• Investments of X ltd represent the cost of 200, 12% debentures of Y ltd acquired at paid up value and the cost of 25000 shares of  Y ltd.  
• Investments of Y ltd include the cost of 200 12%  debentures of X ltd acquire at paid up value. Other investments of Y ltd are considered worth Rs. 610000

Ps:  

• It is given that it is calculated as - Current worth*200/No. of Debentures
• This problem is from PC TULSIAN's advanced accounting Group 2 book, Page No:7.6

Thanks in advance :)