Economics Questions HELP!

You are paid $8.25/hour. you work 35 hours/week for 3 weeks. Your involuntary deductions are FICA (7.65%), federal withholding (13%) and state withholding (9%). How much is your realized income?

You have a credit card with an initial balance of $3,168.00 and an interest rate of 12.75% APR. IF you make no payments on the card for three months, how much is your balance by the end of the third month?

Question

Economics Questions HELP! 

You are paid $8.25/hour. you work 35 hours/week for 3 weeks. Your involuntary deductions are FICA (7.65%), federal withholding (13%) and state withholding (9%). How much is your realized income?

You have a credit card with an initial balance of $3,168.00 and an interest rate of 12.75% APR. IF you make no payments on the card for three months, how much is your balance by the end of the third month?

anonymous · Answer

question: for the first question do you add or multiply the percentages?
(are the percentages applied at the same time or sequentially?)

anonymous · Answer

I think you would multiply the percentages.

zpupster · Answer

first 8.25 *35*3 = Total

Deductions
Total * .0765 =
Total * .13 =
Total * .09 =
do these  and then add the up, deduct them from the total at the top

Total  - deductions =  realized income