Billy Trader opens a brokerage account and purchases 500 shares of Supergrowth.com at $40 per share. He borrows $8,000 from his broker to help pay for the purchase. The margin rate on the loan is 8%. The maintenance margin requirement is 35%.

What is the margin equity in Billy's account when he first purchases the stock?

If the stock price of Supergrowth.com immediately jumps to $50 after his purchase, what is Billy's percentage margin?

If the stock price of Supergrowth.com immediately falls to $35 after his purchase, what is Billy's percentage margin?

If the share price of Supergrowth.com collapses immediately after his purchase, which one of the following scenarios will trigger a margin call from the broker?

Suppose after one year, Billy sells the stock at $45 per share. What is the rate of return on this investment?