A savings account requires a minimum balance of $2000 for interest to be earned at an annual rate of 2 per cent. An account holder has maintained an average balance of $1900 for the first nine months and $3000 for the remaining three months. The account holder does on average 20 transactions per month and pays $0.50 per transaction, although it costs the bank $1.00 per transaction. What average return does the account holder earn on the savings account?

Part a. Find the explicit interest earned by account holder.

Part b. Find implicit earnings.

Part c. Find average deposit maintained during the year.

Part d. Find average interest earned.