A boat covered a distance of 15 km upstream in 5 hours and a distance of 42 km downstream in 6 hours. The speed of the stream in km/h is:
Answer & explanation
Correct answer: option 2
Let the speed of the boat = x and the speed of the stream = y
Boat covers 42 km in 6 hours downstream
In one hour = 7 km distance covered downstream
Boat covers 15 km in 5 hours Upstream
Upstream speed = 3 km per hour
According to the concept =
Downstream =
x + y = 7----(A)
upstream =
x - y = 3----(B)
From A and B we get,
x = 5 and y = 2
So the speed of the stream = 2