given that: Jamie works 40 hours in 5 days.
Then he works 8 hours per day.
total number of days to complete 308 hours is,
[tex]\frac{308}{8}=38.5[/tex]No. of days per month is 30 days.
Therefore Jamie needs 1 month and 8.5 days to complete.
Therefore jamie needs is,
[tex]\frac{38.5}{30}=1.28[/tex]Thus, Jamie needs 1.28 month to complete 308 hours