38% of 4500-25% of ? = 1640

Options

A. 260
B. 270
C. 280
D. 290

Explanation

To solve the equation \( 38\% \text{ of } 4500 - 25\% \text{ of } ? = 1640 \), we can follow these steps:

### Step 1: Convert percentages to fractions
We know that:
- \( 38\% = \frac{38}{100} \)
- \( 25\% = \frac{25}{100} \)

### Step 2: Set up the equation
We can rewrite the equation using these fractions:
\[ \frac{38}{100} \times 4500 - \frac{25}{100} \times ? = 1640 \]

### Step 3: Calculate \( 38\% \text{ of } 4500 \)
Calculate \( \frac{38}{100} \times 4500 \):
\[ \frac{38 \times 4500}{100} = \frac{171000}{100} = 1710 \]

### Step 4: Substitute back into the equation
Now substitute \( 1710 \) back into the equation:
\[ 1710 - \frac{25}{100} \times ? = 1640 \]

### Step 5: Isolate the term with ?
Rearranging gives:
\[ 1710 - 1640 = \frac{25}{100} \times ? \]
\[ 70 = \frac{25}{100} \times ? \]

### Step 6: Solve for ?
To isolate \( ? \), multiply both sides by \( \frac{100}{25} \):
\[ ? = 70 \times \frac{100}{25} \]
\[ ? = 70 \times 4 = 280 \]

### Final Answer
Thus, the value of \( ? \) is \( 280 \).

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