$1.$ Marc, a single taxpayer, earns $$133,500$ in taxable income and $$4,150$ in interest from an investment in city of Birmingham bonds. Using the U$.$S$.$ tax rate schedule for year $2023,$ what is his current marginal tax rate?

$2.$ Leonardo, who is married but files separately, earns $$81,400$ of taxable income. He also has $18,000$ in city of Tulsa bonds. His wife, Theresa, earns $$53,000$ of taxable income. If Leonardo instead has $$31,500$ of additional tax deductions for $2023,$ his marginal tax rate on the deduction would be$.$

$3.$ Manny, a single taxpayer, earns $66,000$ per year in taxable and an additional $$12,100$ per year in city of Boston bonds. What is Manny$$s current marginal tax rate for $2023?$