The following information is available for Bob and Brenda Horton, a married couple filing a joint return, for 2014. Both Bob and Brenda are age 32 and have no dependents. Salaries $180,000 Interest income 12,000 Deductible IRA contributions 11,000 Itemized deductions 22,600 Withholding 32,000 a. What is the amount of their gross income? b. What is the amount of their adjusted gross income? c. What is the amount of their taxable income? d. What is the amount of their tax liability (gross tax)? e. What is the amount of their tax due or (refund due)?