To determine the weight used by a dishonest seller who gains 5% by using false weights, we need to calculate the effective weight based on the relationship between actual and false weight.
Let's denote:
Given that the seller gains a 5% profit using a false weight, the profit percentage can be represented as:
\(\text{Profit Percentage} = \frac{\text{Actual Weight} - \text{False Weight}}{\text{False Weight}} \times 100\%\)
Substitute the known profit percentage:
\(\frac{1000 - x}{x} \times 100\% = 5\%\)
To solve for \(x\), first convert the percentage equation to its decimal form:
\(\frac{1000 - x}{x} = \frac{5}{100}\)
Simplify the equation further:
\(1000 - x = \frac{5}{100} \times x\)
Rearrange to isolate \(x\) on one side:
\(1000 = x + \frac{5}{100} \times x\)
\(1000 = x (1 + \frac{5}{100})\)
\(1000 = x \times \frac{105}{100}\)
Calculate \(x\) by multiplying both sides by \(\frac{100}{105}\):
\(x = 1000 \times \frac{100}{105} = \frac{1000 \times 100}{105}\)
Since \(\frac{1000}{105} \approx 9.52381\), we multiply:
\(x \approx 952.381\) grams.
Thus, the seller uses a weight of approximately 952.381 grams.
Conclusion: The correct answer is 952.381 grams.