4% of `250 xx ?%` of 140=84

Options

A. 12
B. 5
C. 6
D. 8

Explanation

To solve the equation \( 4\% \text{ of } 250 \times ?\% \text{ of } 140 = 84 \), we will follow these steps:

1. **Convert percentages to fractions**:
- \( 4\% \) can be written as \( \frac{4}{100} \).
- Let \( ?\% \) be represented as \( \frac{x}{100} \).

2. **Set up the equation**:
\[ \frac{4}{100} \times 250 \times \frac{x}{100} \times 140 = 84 \]

3. **Simplify the equation**:
- First, calculate \( \frac{4}{100} \times 250 \):
\[ \frac{4 \times 250}{100} = \frac{1000}{100} = 10 \]
- Now substitute this back into the equation:
\[ 10 \times \frac{x}{100} \times 140 = 84 \]

4. **Further simplify**:
- Calculate \( 10 \times 140 \):
\[ 10 \times 140 = 1400 \]
- Now the equation becomes:
\[ \frac{1400x}{100} = 84 \]

5. **Eliminate the fraction**:
- Multiply both sides by 100 to eliminate the denominator:
\[ 1400x = 8400 \]

6. **Solve for \( x \)**:
- Divide both sides by 1400:
\[ x = \frac{8400}{1400} = 6 \]

Thus, the value of \( ? \) is \( 6 \).