 
<translate> Ọsọ n'okpuru mmiri = 40 + 20 = 60 kmph Speed elu mmiri = 40 - 20 = 20 kmph Ya mere, azịza ya bụ (E). <eng> Speed downstream = 40 + 20 = 60 kmph
Speed upstream = 40 - 20 = 20 kmph
Therefore, the answer is (E). 