Margin Account II $[9$ marks$]$

Stock $x$ is currently selling at $$10$ per share. You just sold short $1,000$ shares with a margin account from your broker, and deposited some of your own money as specified by the initial margin requirement. The requirement for the initial margin and minimum margin is $40\%$ and $25\%.$ respectively.

$($a$)[3$ marks$]$ How much money did you deposit in the account? What is the amount of your asset in total?

$($b$)[3$ marks$]$ Immediately after the trade, the stock price drops to $$6.$ What is the percentage return of your investment?

$($c$)[3$ marks$]$ One year has passed, how high can the price go before you receive a margin call?