Charles and Camilla divorced in 2018. Under the terms of the decree, Charles pays Camilla $50,000 in cash in each of the next five years (or until Camilla's death or remarriage). In addition, Charles transferred a castle worth $2,000,000 to Camillain 2018 and will pay $12,000 per year to support their son, Clyde, until he turns 19 years old. What amount (if any) is included in Camilla's gross income in 2021?

Geronimo files his tax return as a head of household for year 2021. If his taxable income is $72,000, what is his average tax rate? (Use tax rate schedule.) (Round your final answer to two decimal places.)

Marc, a single taxpayer, earns $60,000 in taxable income and $5,000 in interest from an investment in city of Birmingham bonds. Using the U.S. tax rate schedule for year 2021, what is his current marginal tax rate? (Use tax rate schedule.)

Kathy is 60 years of age and self-employed. During 2021, she reported $100,000 of revenues and $40,000 of expenses relating to her self-employment activities. If Kathy has no other retirement accounts in her name, what is the maximum amount she can contribute to an individual 401(k) for 2021? Assume she paid $8,478 of self-employment tax for 2021. (Round your final answer to the nearest whole number.)