 
 <translate> Speed upstream = 27/9 = 3 kmph
Speed down stream = 81/3 = 27 kmph
Speed of stream = ½ (27-3) = 12 kmph So the final answer is (A). <ibo> Speed elu mmiri = 27/9 = 3 kmph Speed ala iyi = 81/3 = 27 kmph Ọsọ nke iyi = 1⁄2 (27-3) = 12 kmph Ya mere azịza ikpeazụ bụ (A). 