Frank, age 35, and Joyce, age 34, are married and file a joint income tax return for 2019. Their salaries for the year total $84,800 and they have taxable interest income of $3,900. They have no deductions for adjusted gross income. Their itemized deductions are $24,700. Frank and Joyce do not have any dependents. 

a. What is the amount of their adjusted gross income? 

b. What is their deduction for personal exemptions? 

c. What is the amount of their taxable income?