Assuming that the wage of $12.50 an hour applies to Greg and Darius as a team instead of individually, 9 hours of work would have gotten them:
$12.50/hour × 9 hours = $112.50
If they split the wage in half among themselves, then Greg would have
$112.50 ÷ 2 = $56.25
such that if he spent $15 of it (assuming that's the only money he has), he would now have:
$56.25 - $15 = $41.25
∴ Greg now has $41.25.
