Re: A large ship moving at 14 mph in the river has an investigator cater swimming beside it

My guess is D 3 hour 20 min

In 2 hour 30 min ship will travel 35 miles and cater will complete survey of 70 miles.

In additional 50 min ship will complete ~ 11.5 miles down stream and cater will upstream ~23 miles with assumption upstream speed is equivalent to down stream speed.