 <translate> Saurin jirgin ruwa a cikin ruwa mai nutsuwa = (60 + 100) / 2 = 80 kmph. Saurin rafin = (100-60) / 2 = 20 kmph Saboda haka, amsar ita ce (D). <ibo> Ọsọ ụgbọ mmiri na-agba n'ime mmiri = (60+100) / 2 = 80 kmph. Ọsọ nke iyi = (100-60) / 2 = 20 kmph N'ihi ya, azịza ya bụ (D). 