Pam's prior year (Year 1) income tax liability was $23,000. Her current year (Year 2) AGI did not exceed $150,000. On April 2 of next year (Year 3), Pam, a calendar year taxpayer, timely files her current year individual return, which indicates a $30,000 income tax liability (before reduction for withholding).

In addition, the return indicates self-employment taxes of $2,600. Taxes withheld from Pam's current year (Year 2) salary total $20,000; she has paid no estimated taxes.

1. Will Pam owe a penalty for not paying sufficient estimated taxes? Explain.
2. What amount (if any) per quarter is subject to the penalty, and for what period will the penalty be imposed for each quarter's underpayment?
3. How would your answers to parts a and b change if Pam's current year (Year 2) tax liability (including self-employment taxes) instead were $17,000?