I'm not sure if I am doing this correctly, please show anyformulasand yourcalculations. I really want to know if I'm correct on this so I really appreciate the help!

Suppose required reserve ratio is 10% and John finds a $200 in his shoe box and deposit it in his bank account. A. Compute bank's excess reserves. (2 points) B. Compute the money multiplier. ( 2 points) C. Compute the maximum potential increase in the quantity of money in the economic system (money created by the banking system). (2 points) D. Under what conditions money supply may not increase by the maximum possible amount? (4 points) (Show all formulas and your calculations)