The marked questions ? are right ones. I need the steps and explaination.

7. Lotta Leveridge purchased 200 shares of PPG Inc. from you at $60 per share. She gave you a check for the initial margin requirement. PPG announces that it is selling Magic Meditation Machine in Japan, and its stock appreciates on the news to $75. How much cash can Lotta withdraw after this market move? a. SO b $1,000 .Lota Leveridge purchasef 200 sharcs of PPG Inc.from you at $60 per share. She gave you a ument PG ammoucs that it s seng millions of its new $1,500 $3,000