We will have to solve as follows:
*He has a constant $500
*If we divide $500 by 40 hours, we will get he makes $12.5 an hour. So, working 30 hours in the weekend he made $375.
*He sold 22 t-shirts, all worth $264.
From this, we have he made:
$500 + $375 + $ 264 = $1139