Answer:
His total hours he worked is;
21
Explanation:
The of hours between 9:00 A.M. and 4:30 P.M. are;

Sum of the hours Harold Crispen spends at the workplace on a workday = (1 + 1 + 1 + 1 + 1 + 1 + 1 + 0.5) hours = 7.5 hours
The time Harold Crispen take for launch each workday = 0.5 hour
The number of hours Harold Crispen spend working each day = (7.5 - 0.5) hour
The number of hours Harold Crispen spend working each day = 7.0 hours/day
The number of days he worked = Monday + Tuesday + Thursday = 3 days
The total hours he worked = (The number of hours he works each day) × (The number of days he worked)
His total hours he worked = 7.0 hours/day × 3 days = 21.0 hours.