The speed of a boat in still water is 10 km/hr. It covers (upstream) a distance of 45 km in 6 hour. The speed (in km/hr) of the stream is?
Answer & explanation
Correct answer: option 3
Upstream speed = \(\frac{45}{6}\) = 7\(\frac{1}{2}\) km/hr = Spped of boat - speed of current
Speed of boat - speed of current = 7\(\frac{1}{2}\) km/hr
10 km/hr - speed of current = 7\(\frac{1}{2}\) km/hr
speed of current = 2\(\frac{1}{2}\) km/hr