A. 13 % B. 11 1/9 % C. 11.25 % D. 12 1/9 % Explanation:Advertisement Let the C.P of the article be Rs 1 per gram C.P of 900gm = Rs 900, S.P of 1000gm = Rs 1000 Gain % = (100/900 × 100)% = 100/9 % = 11 1/9 % Advertisement