Answer:
$21.20
Step-by-step explanation:
To solve this problem, we can use the equation provided in the question:
[tex]c=1.06p[/tex]
c = total cost
p = price (before tax)
Now, lets plug in the values into the equation:
[tex]c=1.06p[/tex]
[tex]c=1.06(20)[/tex]
[tex]c=21.2[/tex]
The total cost of the $20 shirt including sales tax is $21.20.