You want to buy $200$ shares of MNO using a $60\%$ margin. The maintenance margin is $30\%.$ The current price of MNO is $$60.$ How much money did you have to invest today and how much money did you borrow? What price will trigger a margin call? What is the overall rate of return on your investment if you sell the stock $6$ months later at a price of $$66?$ What is the overall rate of return on your investment if you sell the stock $6$ months later at a price of $$55.($assume the margin loan $($call rate$)$ rate is $7\%$ per year$).($The stock did not pay a dividend.$)$

You want to short sell $200$ shares of PQR using a $60\%$ margin. The maintenance margin is $30\%.$ The current price of $PQR$ is $$80.$ How much money did you have to invest today? What price will trigger a margin call? What is the overall rate of return on your investment if the stock is selling at a price of $$88$ in $1$ year? What is the overall rate of return on your investment if the stock is selling at a price of $$72$ in $1$ year? $($The stock did not pay a dividend$).$