$A$ 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 $Rs.$)

Meena bought $Rs. 36000$ of $7\frac{1}{2} \%$ stock at $92$ and sold it when its price rose to $Rs. 93 \frac{3}{4}$. Find out her gain percent.

How many shares of market value $Rs. 25$ each can be purchased for $Rs. 12750$,given that the brokerage is $2\%$?

$A$ man sells $5000$ common shares of Company $X$ (each of par value $Rs. 10$), which pays a dividend of $20\%$, at $Rs. 30$ per share. He invests the sale proceeds in ordinary shares of Company $Y$ (each of par value $Rs. 25$) that pays a dividend of $15\%$. If the market value of a share of Company $Y$ is $Rs. 40$, find out the number of shares of Company $Y$ purchased by the man.

$12500$ shares, of par value $Rs.\, 20$ each, are purchased from Ram by Mohan at a price of $Rs.\, 25$ each. Find out the amount required to purchase the shares. If Mohan further sells the shares at a premium of $Rs.\, 11$ each, then find out his gain in the transaction. (in $Rs.$)