This year Lloyd, a single taxpayer, estimates that his tax liability will be $11,950. Last year, his total tax liability was $16,300. He estimates that his tax withholding from his employer will be $9,035.

a. How much does Lloyd need to increase his withholding by (for the year), in order to avoid the underpayment penalty?

b. Zach is 29 years old and his AGI is $10,100.

c. Zach is 29 years old and his AGI is $18,600.

d. Zach is 24 years old and his AGI is $6,200.