A boat goes 10 km upstream in 50 minutes, and the speed of the stream is 3 kmph, Find the speed of the boat in still water. (in kmph)
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 15.
Let's assume the speed of the boat in still water = x
Given that:
The speed of the stream is 3 kmph
So, upstream speed = x - 3
The boat goes 10 km upstream in 50 minutes:
Time = Distance/Speed
⇒ 50/60 = 10/(x - 3)
⇒ 5x - 15 = 60
⇒ x = 75/5 = 15
So, speed of boat in still water = 15 km/h