Arnell bought 200 shares of Black Petroleum Company for $95 per share and paid a commission of $60. He sold the stock five years later for $120 per share and paid $75 commission. While he held the stock, it paid (in total) dividends of $5.50 per share. What was Arnell's total dollar return on this stock

Atennis club charges a monthly membership fee of $150 and charges it members $10 per hour to use a court. there's also $500 fee to become a member. stella joined the tennis club last spring, and she has been a member for 5 months. she has been playing 10 hours of tennis each month. stella values an hour of her time at $20. during a boring afternoon meeting, stella thinks about reserving a court to work on her serve for an hour tonight. what's stella's opportunity cost of working on her serve for an hour?