Answer:
-1 hour
Explanation:
Assuming 7:00 AM, to find the answer first we have to find 6 hours added to his starting time. Cont till 12 p.m you get 7, 8, 9. 10, 11, and 12 p.m. You get 5 hours now from 12 count until you get a total of 6 hours so 12, 1 PM.
Meaning that his work stops at 1 pm so he worked an extra 1 hour so he has -1 hour left.