Alex takes a shoet position ok Microsoft stock at $1000 per share. he sells 100 shares short at $1000 per share. The short sale has an IMR equals to 50% and MMR equals to 30%.

1- how much does Alex have to deposit in his account after taking the short position?

2- at what price would Alex double the valueof hus investment?

3- by what % would the price have to rise for Alex to be subject to a margin call?