A dishonest dealer professes to sell his goods at the cost price but uses a false weight of 850 g instead of 1 kg. His gain percent is.
एक बेईमान व्यापारी अपनी वस्तुएँ क्रय मूल्य पर बेचने का दावा करता है। परंतु 1 किग्रा. की जगह 850 ग्राम का नकली बाट प्रयोग करता है। उसका लाभ प्रतिशत है -

Options

A. `A. 11 11/17 %`
B. `B. 17 12/17 %`
C. `C. 17 11/17 %`
D. `D. 71 11/17 %`

Explanation

To solve the problem, we need to determine the gain percentage of the dishonest dealer who sells 850 grams of goods while claiming to sell 1 kg (1000 grams) at the cost price.

### Step-by-Step Solution:

1. **Understand the Cost Price (CP):**
Let's assume the cost price of 1 kg (1000 grams) of goods is ₹100.

**Hint:** Assume a convenient cost price to simplify calculations.

2. **Calculate the Cost Price of 850 grams:**
Since the cost price of 1 kg is ₹100, the cost price of 850 grams can be calculated as follows:
\[ \text{CP of 850 grams} = \left(\frac{850}{1000}\right) \times 100 = ₹85 \]

**Hint:** Use the ratio of the weights to find the cost price of the smaller quantity.

3. **Selling Price (SP):**
The dealer sells 850 grams at the cost price of 1 kg, which is ₹100.

**Hint:** The selling price is what the dealer claims to sell the goods for.

4. **Calculate the Gain:**
Gain can be calculated using the formula:
\[ \text{Gain} = \text{SP} - \text{CP} \]
Substituting the values:
\[ \text{Gain} = 100 - 85 = ₹15 \]

**Hint:** Gain is simply the difference between selling price and cost price.

5. **Calculate Gain Percentage:**
Gain percentage is calculated using the formula:
\[ \text{Gain Percentage} = \left(\frac{\text{Gain}}{\text{CP}}\right) \times 100 \]
Substituting the values:
\[ \text{Gain Percentage} = \left(\frac{15}{85}\right) \times 100 \approx 17.65\% \]

**Hint:** To find the gain percentage, divide the gain by the cost price and multiply by 100.

### Final Answer:
The gain percentage of the dishonest dealer is approximately **17.65%**.