13. Paul and Olivia filed a joint return and reported modified AGI of $192,000. They have two qualifying children for the purposes of the child tax credit. What is the amount of their child tax credit? What is the amount of their credit if their modified AGI is $432,000?

15. Leonardo's filing status is head of household. He has modified AGI of $33,000, and he made a $3,000 contribution to his IRA. What is the amount of his retirement savings contributions credit? What would the credit be if he had a filing status of single?

19. What is the definition of qualifying child for purposes of the Earned Income Credit?

20. Briefly explain the difference between a refundable and nonrefundable tax credit and give three examples of tax credits that may be refundable?

22. The amount of the premium tax credit is the lesser of what two factors?