Answer:
The answer would be Decrease, Decrease.
Step-by-step explanation:
Increasing your 401 k deduction, will Decrease your gross pay and Decrease your Federal Taxes in the current year.
Gross pay of a person is his pay without deductions of any taxes. When taxes are deducted from the salary, the remaining amount is called the Net Salary. So when 401 k are deducted from the salary, the gross pay will decrease, and in turns, the federal taxes will also decrease, because a percentage of taxes is deducted from the gross salary. So when gross salary decreases, the taxes decreases and vice versa.