In 2016, Carson is claimed as a dependednt on his parent's tax return. His parent's ordinary income marginal tax rate is 28%. Carson's parents provided most of his support. What is Carson's tax liability for the year in each of the following alternative circumstances?

a. Carson is 17 years old at school-end and earned $12,000 from his summer job and part-time job after school. This was his only source of income.

b. Carson is 23 years old at year-end, He is a full-time student and earned $12,000 from his summer internship and part-time job. He also received $5,000 of qualified dividend income.