Joyce is a single, cash method taxpayer. On April 11, 2018, Joyce paid $120 in state income taxes with her 2017 state income tax return. During 2018, Joyce had $1,600 in state income taxes withheld. On April 13, 2019, Joyce paid $200 with her 2018 state tax return. During 2019, she had $2,100 in state income taxes with-held from her paycheck. Upon filing her 2019 tax return on April 15, 2020, she received a refund of $450 for excess state income taxes withheld. Joyce had total AG1 in 2019 and 2020 of $51,000 and $53,500, respectively. In 2019, Joyce also paid $10,500 in qualified residence interest. a. What is the amount of state income taxes Joyce may include as an itemized deduction for 2018? b. What is Joyce's allowed itemized deduction for state income taxes for 2019? c. What is Joyce's taxable income for 2019?