A dishonest trader says to customers that he sells his goods at a cost price, but he uses a false weight and gains 12.5% as profit. How many grams does he use to weigh 1 kg?

Answer: Option D

Let 1000 gm price = Rs. 1000
12.5% of 1000 = Rs. 1125
When he gets profit of 12.5% on 1000 gm
$$\begin{array}{rl}& \text{Then, }\frac{1000}{1125}\times 1\text{kg}\\ & =\frac{1000\times 1000\text{ gm}}{1125}\\ & =888.8\text{ gm}\end{array}$$