A boat covers 18 km downstream in 3 hours and the same distance upstream in 6 hours. The speed of the boat in still water is __________.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 4.5 km/h.
Downstream speed = 18/3 = 6 km/h
Upstream speed = 18/6 = 3 km/h
Boat speed = (Downstream + Upstream)/2 = (6 + 3)/2 = 4.5 km/h