If 25:35 :: 45 : x, then the value of x is

Options

A. 63
B. 72
C. 54
D. none of these

Answer

To solve the problem, we need to find the value of \( x \) in the proportion \( 25:35 :: 45:x \). This means that the ratio of 25 to 35 is the same as the ratio of 45 to \( x \).

### Step-by-Step Solution:

1. **Set up the proportion**:
\[ \frac{25}{35} = \frac{45}{x} \]

2. **Cross-multiply**:
\[ 25 \cdot x = 35 \cdot 45 \]

3. **Calculate \( 35 \cdot 45 \)**:
\[ 35 \cdot 45 = 1575 \]

4. **Rewrite the equation**:
\[ 25x = 1575 \]

5. **Solve for \( x \)**:
\[ x = \frac{1575}{25} \]

6. **Divide \( 1575 \) by \( 25 \)**:
\[ x = 63 \]

Thus, the value of \( x \) is \( 63 \).