Explanation:

- The shopkeeper uses a 940 gm weight instead of the standard 1 kg (1000 gm). This means he delivers less than a kilogram to customers.

- When he claims to sell 1 kg, he actually sells only 940 gm.

- There's a deceptive gain because he charges for 60 gm extra that isn't delivered.

- Stated profit is 4%, but this is based on the perceived cost, which is less due to the weight discrepancy.

- To find the actual profit:

- Calculate the percentage based on the real cost (940 gm as opposed to 1 kg).

- Use this formula: $(\frac{1000\text{ gm (claimed weight)}}{940\text{ gm (actual weight)}})\times (1+0.04)-1$.

- Solving gives an actual profit of approximately 10.64%.

- Correct Answer: Option 3 - 10.64%