The HCF and LCM of two numbers are 145 and 2175 respectively. If the first number is 435, find the second number.

Answer

To find the second number when the HCF (SCF) and LCM of two numbers are given, we can use the relationship between these values. The formula states that:

\[ \text{Product of the two numbers} = \text{HCF} \times \text{LCM} \]

Given:
- HCF = 145
- LCM = 2175
- First number (let's call it A) = 435

We need to find the second number (let's call it B).

### Step-by-Step Solution:

1. **Use the formula for the product of the two numbers**:
\[ A \times B = \text{HCF} \times \text{LCM} \]

2. **Substitute the known values into the formula**:
\[ 435 \times B = 145 \times 2175 \]

3. **Calculate the right-hand side**:
First, we need to calculate \( 145 \times 2175 \).
\[ 145 \times 2175 = 315375 \]

4. **Now, we have the equation**:
\[ 435 \times B = 315375 \]

5. **To find B, divide both sides by 435**:
\[ B = \frac{315375}{435} \]

6. **Perform the division**:
\[ B = 725 \]

### Final Answer:
The second number is **725**.