15 `xx` ? + 20% of 450 = 360

Options

A. 12
B. 20
C. 24
D. 18

Answer

To solve the equation \( 15 \times ? + 20\% \text{ of } 450 = 360 \), we can follow these steps:

### Step 1: Calculate 20% of 450
First, we need to find 20% of 450.

\[ 20\% \text{ of } 450 = \frac{20}{100} \times 450 = \frac{1}{5} \times 450 = 90 \]

### Step 2: Substitute the value back into the equation
Now, we substitute \( 90 \) back into the equation:

\[ 15 \times ? + 90 = 360 \]

### Step 3: Isolate the term with the question mark
Next, we need to isolate \( 15 \times ? \) by subtracting \( 90 \) from both sides:

\[ 15 \times ? = 360 - 90 \]

\[ 15 \times ? = 270 \]

### Step 4: Solve for the question mark
Now, we divide both sides by \( 15 \) to find the value of \( ? \):

\[ ? = \frac{270}{15} \]

Calculating \( \frac{270}{15} \):

\[ ? = 18 \]

### Final Answer
Thus, the value of \( ? \) is \( 18 \).

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