Final answer:
The total cost for 400 copies of Roger's resume, including a 6% sales tax, is $43.99.
Step-by-step explanation:
To find the total cost including sales tax for printing 400 copies of Roger's resume, we need to calculate the initial cost and then add the 6% sales tax.
First, the cost for the first 200 copies is $21.50. For the additional 200 copies (which is 2 groups of 100 copies), the print shop charges $10 per 100 copies. So, the additional cost will be 2 × $10 = $20.
The initial total before tax is $21.50 + $20 = $41.50.
Now we calculate the sales tax: 6% of $41.50 equals 0.06 × $41.50 = $2.49.
The total cost including sales tax is $41.50 + $2.49 = $43.99.