Numbers Finder by Product and HCF

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Calculate Two Numbers Based on Their Product and HCF

Result

How to Calculate Two Numbers Based on Their Product and HCF

Assume the two numbers are \( x \) and \( y \), with their product denoted as \( P \) and their highest common factor as \( \text{HCF} \).

Step-by-Step Derivation

1. Understanding HCF

Let \( x = k \times a \) and \( y = k \times b \), where \( k \) is the highest common factor (\( \text{HCF} \)), and \( a \) and \( b \) are coprime integers (their greatest common divisor is 1).

2. Establishing the Relationship

Using the product \( P \), we get: \( x \times y = (k \times a) \times (k \times b) = k^2 \times (a \times b) = P \) From this, we derive: \( a \times b = \frac{P}{k^2} \)

3. Finding the Coprime Pair \( a \) and \( b \)

Factorize \( a \times b \) and identify all pairs of factors that are coprime integers.

4. Calculating \( x \) and \( y \)

Use the proportionality constant \( k \) to compute the two numbers: \( x = k \times a \) \( y = k \times b \)

Examples

Example 1: Find two numbers whose product is 2025 and HCF is 15.

Solution:

1. Identify the proportionality constant:

\( k = HCF = 15 \)

2. Compute \( a \times b \):

\( a \times b = \frac{2025}{15^2} = \frac{2025}{225} = 9 \)

3. Find coprime pairs for \( a \times b = 9 \):

Factorize 9 into pairs:

(1, 9)

(3, 3)

Among these, (1, 9) is coprime.

4. Calculate \( x \) and \( y \):

\( x = 15 \times 1 = 15 \)

\( y = 15 \times 9 = 135 \)

Result: The two numbers are 15 and 135.

Example 2: Find two numbers whose product is 19200 and HCF is 40.

Solution:

1. Identify the proportionality constant:

\( k = HCF = 40 \)

2. Compute \( a \times b \):

\( a \times b = \frac{19200}{40^2} = \frac{19200}{1600} = 12 \)

3. Find coprime pairs for \( a \times b = 12 \):

Factorize 12 into pairs:

(1, 12)

(2, 6)

(3, 4)

Among these, (1, 12) and (3, 4) are coprime.

4. Calculate \( x \) and \( y \):

\( x_1 = 40 \times 1 = 40 \)

\( y_1 = 40 \times 12 = 480 \)

\( x_2 = 40 \times 3 = 120 \)

\( y_2 = 40 \times 4 = 160 \)

Result: The two numbers are (40, 480) or (120, 160).