What is the downstream speed of the boat?
I. The speed of the boat is 15 km/hr.
II. The boat rows up a river 30 km in 6 hours.
we know that speed = distance/Time From statement II Upstream speed = 30/6 = 5 km/hr From both I and II, Speed of boat = 1/2 (Downstream + upstream speed) 15 = 1/2 (downstream + 5) 30 = downstream +5 Downstream speed = 25 km/hr Therefore, both statement I and statement II together are necessary to answer the question.