Assume that face value = Rs.100
Dividend per share = Rs.8.5 (as it is 8.5% stock)
By investing Rs.11000, earnings = Rs.1900
To get an earning of Rs.8.5, investment required = (11000*8.5)/1900 = Rs.49.21
market value of Rs. 100 stock = Rs.(49.21- 1/4) = Rs.48.96