Answer:
$180.11
Step-by-step explanation:
You want the net income after taxes and travel expenses are subtracted from earnings of $13 per hour for 20 hours over 4 days.
Your gross wages are ...
($13/h) × (20 h) = $260
The tax deductions total 7.65% +10% = 17.65% of your gross wages. The amount taken out for taxes is ...
$260 × 0.1765 = $45.89
Your take-home pay is the amount after taxes are deducted from your gross pay:
net pay = $260.00 -45.89 = $214.11
After you pay for your travel expenses, the remaining amount is your net income. The travel expenses are $8.50 per day for 4 days, or ...
travel expense = ($8.50/day) × (4 days) = $34.00
net income = net pay - travel expense
net income = $214.11 -34.00 = $180.11
Your net income after travel expenses is $180.11.
__
Additional comment
We cannot think of an error that will result in a difference of $30. Such an error might mean you are using $1.00 per day for travel expense instead of $8.50 per day, for example. That error is sufficiently large and obvious that it seems unlikely.