Aboat sails along the shore. to an observer, the boat appears to move at a speed of 11 m/s, and a man on the boat walking forward appears to have a speed of 12.4 m/s. how long does it take the man to move 6 m relative to the boat?

You first subtract the speed at which the man is moving (11 m/s) from the rate the boat is moving (12.4 m/s). Which equals 1.4, then divide it by 6 meters, as the man is moving relative to the boat.

It therefore equals 4.29 s

i don't know that i agree with that but what's the question ?