On April 3, 2008, Mark filed his 2007 Income tax return, which showed a tax due of $80,000. On June 1, 2010, he filed an amended retrun for 2007 that showed an additional tax of $10,000. Mark paid the additional amount. On May 18, 2011, Mark filed a claim for a 2007 refund of $45,000. a. If Mark's claim for a refund is correct in amount, how much tax will he recover? b. What is the period that government paid itnerest runs with respect to Mark's claim for a refund? c. How would you have advised him differently