David and Ruby are engaged and plan to get married. During 2021, David is a full-time student and earns $9,400 from a part-time job. With this income, student loans, savings, and nontaxable scholarships, he is self-supporting. For the year, Ruby is employed and has wages of $81,400. Click here to access the standard deduction table to use. Click here to access the Tax Rate Schedules. If an amount is zero, enter, "0". Do not round your intermediate computations. Round your final answer to nearest whole dollar. a. Compute the following: Gross income and AGI Standard deduction (single) Taxable income Income tax David Ruby Filing Single Filing Single b. Assume that David and Ruby get married in 2021 and file a joint return. What is their taxable income and income tax? Round your final answer to nearest whole dollar. Gross income and AGI Standard deduction (married, filing jointly) Taxable income Income tax Married Filing Jointly c. How much income tax can David and Ruby save if they get married in 2021 and file a joint return