 
<translate> N'abalị mbụ: 320{\displaystyle 320{\text{1}}} = 80. 320 - 80 bụ 240. N'abalị nke abụọ: 240: 1/6 = 40. 240 - 40 = 200. N'abalị nke atọ: 200.30 = 60. 200 - 60 = 140 ọbọgwụ fọdụrụ. N'ihi ya, azịza ya bụ 140. <eng> First night:320(1 / 4) = 80. 320 - 80 = 240. Second night:240(1 / 6) = 40. 240 - 40 = 200. Third night:200(.30) = 60. 200 - 60 = 140 ducks remain.
Therefore, the answer is 140. 