Amy files her current year tax return on August 13 of the following year. She pays the amount due without requesting an extension. The tax shown on her return is $24,000. Her current year wage withholding amounts to $15,000. Amy pays no estimated taxes and claims no tax credits on her current year return.

a. What penalties will the IRS likely impose on Amy (ignoring the penalty for underpayment of estimated taxes)? Assume Amy committed no fraud and that any penalty and interest period begins on April 16.

b. On what dollar amount, and for how many days, will Amy owe interest?