He works average 35.483... hours per day.
<em><u>Explanation</u></em>
Suppose, Larry works average
hours per day.
As he works for 15 days, so the <u>total number of hours</u> he worked
hours.
Given that, he works 15 days for a <u>total of 532.25 hours</u>. So the equation will be....

So, he works average 35.483... hours per day.