A Boat Crosses a River Which Is Flowing at 6

Multiple Choice

A boat crosses a river which is flowing at 6.0 m/s.The boat travels directly across the river from A to B and the speed of the boat relative to the river is 9.0 m/s.If it takes the boat 10.0 seconds to cross the river,how wide is the river?

A) 108.1 m
B) 89.2 m
C) 67.1 m
D) 60.0 m
E) 150.0 m