A motorboat goes 24 km in 2 hours along the stream and 10 km in 1 hour against the stream. The speed of the motorboat in kilometres per hour is:
Answer & explanation
Correct answer: option 3
Let the speed of the boat = x and the speed of the stream = y
Boat covers 24 km in 2 hours
In one hour = 12 km distance covered downstream
Upstream speed = 10 km per hour
According to the concept =
Downstream =
x + y = 12----(A)
upstream =
x - y = 10----(B)
From A and B we get,
x = 11 and y = 1
So the speed of the boat = 11