?% of 1020 - 15% of 1220 = 72

Options

A. 20
B. 18
C. 25
D. 28

Answer

To solve the equation \( ?\% \text{ of } 1020 - 15\% \text{ of } 1220 = 72 \), we will follow these steps:

### Step 1: Define the variable
Let \( x \) represent the percentage we are trying to find. Thus, we can rewrite the equation as:
\[ \frac{x}{100} \times 1020 - \frac{15}{100} \times 1220 = 72 \]

### Step 2: Calculate \( 15\% \text{ of } 1220 \)
First, we need to calculate \( 15\% \text{ of } 1220 \):
\[ 15\% \text{ of } 1220 = \frac{15}{100} \times 1220 = \frac{15 \times 1220}{100} = 183 \]

### Step 3: Substitute back into the equation
Now substitute \( 183 \) back into the equation:
\[ \frac{x}{100} \times 1020 - 183 = 72 \]

### Step 4: Isolate the term with \( x \)
Add \( 183 \) to both sides of the equation:
\[ \frac{x}{100} \times 1020 = 72 + 183 \]
\[ \frac{x}{100} \times 1020 = 255 \]

### Step 5: Solve for \( x \)
Now, to find \( x \), multiply both sides by \( \frac{100}{1020} \):
\[ x = \frac{255 \times 100}{1020} \]

### Step 6: Simplify the fraction
Now we simplify \( \frac{255 \times 100}{1020} \):
\[ x = \frac{25500}{1020} \]
To simplify, divide both the numerator and denominator by \( 255 \):
\[ x = \frac{100}{4} = 25 \]

### Conclusion
Thus, the value of \( x \) is \( 25 \). Therefore, the answer to the question is:
\[ \boxed{25} \]

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