Chuck, a single taxpayer, earns $75,000 in taxable income and $10,000 in interest from an investment in City of Heflin bonds. (Use the U.S. tax rate schedule 2021.)

1. If Chuck earns an additional $40,000 of taxable income, what is his marginal tax rate on this income?
2. What is his marginal rate if, instead, he had $40,000 of additional deductions?