(17) A courier starts the day in London and makes two round trips to Prague in the day. When she arrives at either airport, she takes the next available flight back.
The daily timetable is shown below (all times are local):
How long is the courier’s day from first take-off to last landing?
A 4 hours 50 minutes
B 8 hours 5 minutes
C 8 hours 20 minutes
D 11 hours 20 minutes
E 14 hours 35 minutes