I think I might have solved this.
Work = Rate x Time
1 job = 8 Rate (because 8 people) x 42 days
Solving for the rate: R = 1/336
Therefore, the new equation taking into consideration that one worker is now work half days:
1 job = 7.5 rate x Time
1 job = 7.5 (1/336) x Time
Solving for time, it is 44.8 days. Is this the correct way to solve it?
Thanks in advance!