Find the income by investing $Rs. 81000$ in $9 \%$ stock at $135$. (in $Rs.$)

Ram invested $Rs.\, 88008$ in $9 \frac{1}{2} \%$ stock at $112$ (Brokerage: $Rs.\, 2$). Find out the annual income of Ram from this investment (in $Rs.$).

$A$ man bought $Rs. 20000$ of $5\%$ stock at $90$ and sold it when its price rose to $Rs. 93 \frac{3}{4}$. Find out his gain percent.

Find out the investment required to get an income of $Rs. 1938$ from $9 \frac{1}{2} \%$ stock at $90$ (Brokerage $1 \%$). (in $Rs.$)

$A$ man invested $Rs. 50490$ in $5\%$ stock at $99$ and sold it when the price rose to $Rs. 102$. He invested the sale proceeds in $8\%$ stock at $96$. Find out the change in the man's income (Brokerage: $Rs. 3$).

Sonu invested $10 \%$ more than Mona. Mona invested $10 \%$ less than Raghu. If the total sum of their investment is $Rs. 5780$,how much amount did Raghu invest? (in $Rs.$)