Bill and Mary plan to marry in December 2013. Bill's salary is $32,000 and he owns his own residence. His itemized deductions total $12,000. Mary's salary is $39,000. Her itemized deductions total only $1,600 as she does not own her own residence. For purposes of this problem, assume 2014 tax rates exemptions, and standard deductions are the same as 2013.

a. What will their tax be if they marry before year-end and file a joint return?

b. What will their combined taxes be for the year if they delay the marriage until 2014?

c. What factors contribute to the difference in taxes?