His hourly rate is $13.75
Here, we want to get Piper's hourly pay at work
Let the hourly rate be h
Thus, for working 20 hours, the amount for this will be; 20 * h = 20h
Now, out of the $1500 sales, he is entitled to 16%
That means;
[tex]\frac{16}{100}\times\text{ 1500 = 240}[/tex]Thus, we have it that;
[tex]\begin{gathered} 20h\text{ + 240 = 515} \\ 20h\text{ = 515-240} \\ 20h\text{ = 275} \\ h\text{ = }\frac{275}{20} \\ h\text{ = \$13.75} \end{gathered}[/tex]