Aastha wants to short 500 shares of LC at $18 a share, while Brian wants to buy 500 at the same price on margin. If both face an initial margin requirement of 60% and a maintenance margin requirement of 50%, determine how much cash each must have in order to enter this transaction. Suppose that each of them has exactly the required amount of cash, and they enter their desired positions. (a) Construct the balance sheets for both traders respectively. (b) Find the price at which Aastha will get a margin call, and the price at which Brian will get a margin call