What would be the net annual cost of the following checking accounts? a. Monthly fee, $2.75; processing fee, 50 cents per check; checks written, an average of 30 a month. (Do not round intermediate calculations. Round your answer to 2 decimal places. Input the amount as a positive value.)

For this one, I got $213.

b. Interest earnings of 4 percent with a $450 minimum balance; average monthly balance, $600; monthly service charge of $20 for falling below the minimum balance, which occurs five times a year (no interest earned in these months). (Do not round intermediate calculations. Round your answer to 2 decimal places. Input the amount as a positive value.)

Not sure how to do this one exactly.