 <translate> Speed downstream = 50 + 20 = 70 kmph
Speed upstream = 50 - 20 = 30 kmph
Therefore, the answer is (A). <yor> Iyara tó wà ní ìsàlẹ̀ odò = 50 + 20 = 70 kmph Iyara ti o wa ni oke = 50 - 20 = 30 kmph Nítorí náà, ìdáhùn náà ni (A). 