Barrett and Betina Are Planning to Be Married on December

Barrett and Betina are planning to be married on December 26, 2014. Barrett's salary for 2014 is $42,000 and Betina's is $40,000. Barrett pays mortgage interest of $7,200 and property taxes of $1,800; Betina has $400 of charitable contributions. Barrett earns interest of $1,450 on a savings account and makes a deductible for AGI contribution to his IRA of $2,000. Betina makes a $1,000 deductible contribution to her IRA. Amounts withheld for State taxes are $1,900 for Barrett and $1,800 for Betina. Based on the above information, answer the following questions to help Barrett and Betina prepare their 2014 tax return they will file jointly and have no other dependents):
a. What is their Adjusted Gross Income AGI) for 2014?
b. What is their taxable income and tax liability?
c. If Barrett and Betina don't get married until January 2015, what is Barrett's taxable income and tax liability?
d. If Barrett and Betina don't get married until January 2015, what is Betina's taxable income and tax liability?
e. From a purely tax standpoint, should Barrett and Betina get married in December or January?