A dishonest dealer claims to sell his goods at the cost price but uses a false weight of 900 gm for 1 kg what is his gain percent?

A. 13 %
B. 11 1/9 %
C. 11.25 %
D. 12 1/9 %
Explanation:
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 %