suppose you purchase some shares of MLP common stock on margin at $50 per share . The initial margin is 60% and the maintenance margin is 30%.( assume the stock pays no dividends and ignore interest on the margin loan)

a) assume you borrowed $ 3000 from the broker for the purchase with60% margin. How many shares have you bought ?

b) what is the maximum price to trigger a margin call ??

Please write with the details .