A proposed state income tax would require individuals with incomes of $15,000 or less to pay no tax and those with incomes above $15,000 to pay a tax of 10 percent only on the part of their income that exceeds $15,000

a. Could an individual pay an average tax rate of 7.5 percent under this system?

b. Could an individual pay an average tax rate of 10 percent under this system?

c. What average and marginal tax rates would individual with these income levels face: $10,000, $20,000, $40,000 and $150,000?

Explain each of your answers and provide examples to justify your conclusions.