Answer:
The first one/$9 an hour job.
Explanation:
For every 32 hours he works at the $9 per hour job he makes $288.
On the other hand, for every 32 hours he works at the $7 per hour job he only makes $224.
So the only one that'll work where he gets at least $251 is the $9 an hour job.
Hope this helps and have a nice day!