1. Tom filed his federal income tax return for 20x4 on November 29, 20x5. He had not applied for an extension of time to file. He was married but filed separately from his spouse. The return showed adjusted gross income of $250,000 and a tax liability of $70,000. His employer had withheld $35,000 in federal income tax from his compensation. His return for 20x3 had reflected a tax liability of $50,000, and an overpayment of $5,000, which he had directed be applied to his 20x4 tax liability. He had also timely paid estimated tax for 20x4 of $10,000, in four equal quarterly installments of $2,500 each. He paid the balance of the tax due for 20x4 with his return.

(b) If so, how much will the additions be?

(c) Is Tom liable for an addition to tax for underpayment of estimated tax?