The effective speed of a boat is 15.2 km/h against the stream and 20.8 km/h along the stream. Find the speed of the stream.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 2.8 km/h.
Let speed of boat be v km/h and speed of stream be u km/h.
Given that, speed of boat along the stream, v + u = 20.8 .....(1)
and speed of boat against the stream, v - u = 15.2 ....(2)
Subtracting equation (2) from (1),
⇒ 2u = 5.6
⇒ u = 2.8
Hence, speed of stream, u = 2.8 km/h