The market value of a 10.5% stock, in which an income of Rs. 756 is derived by investing Rs. 9000, brokerage being 14 % is :

For an income of Rs.756, investment = Rs.9000 

For an income of Rs. $\frac{21}{2}$, investment =  $Rs.\frac{9000}{756}*\frac{21}{2}$ = Rs.125 

For a Rs.100 stock, investment = Rs.125.

Market value of Rs. 100 stock  =  $Rs.125-\frac{1}{4}$ = Rs. 124.75