Answer:
3.49km/hr
Step-by-step explanation:
This train is moving at 50km/hr
Distance = length of train + distance of tunnel
= 3 km + 40 km
= 43 km
Time taken by train to get to tunnel
Time = distance / velocity
Time = 43 km/50km perhour
= 0.86
How fast will stunt double have to run?
Velocity = 3km/0.86
= 3.49 km/hr
The stunt double will have to run as fast as 3.49 kilometer per hour