A boat covers a certain distance downstream in 2 hours, while it returns back in 2 hours. If the speed of the stream is 3 km/h, what is the speed of the boat in still water?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 27 km/h.
Let the speed of the boat in still water = x km/h
2(x + 3) = (x - 3) = 2.5(x - 3)
⇒ 2x + 6 = 2.5x - 7.5
⇒ 0.5x = 13.5
⇒ x = 13.5/0.5 = 27 km/h