For two positive integers, HCF × LCM equals:
ATwice the smaller
BTheir sum
CProduct of the numbers
DSmaller / larger
Answer & Solution
Correct answer: C. Product of the numbers
The relationship between the Highest Common Factor (HCF) and the Least Common Multiple (LCM) of two positive integers $a$ and $b$ is defined by a fundamental mathematical identity.
### Formula:
For any two positive integers $a$ and $b$:
$$HCF(a, b) \times LCM(a, b) = a \times b$$
### Step-by-Step Breakdown:
1. **Identify the Terms**: Let the two numbers be $a$ and $b$.
- **HCF** (Highest Common Factor) is the largest positive integer that divides each of the integers.
- **LCM** (Least Common Multiple) is the smallest positive integer that is divisible by both numbers.
2. **Verification with an Example**:
Let $a = 12$ and $b = 18$.
- Prime factorization of $12 = 2^2 \times 3$
- Prime factorization of $18 = 2 \times 3^2$
- $HCF(12, 18) = 2^1 \times 3^1 = 6$
- $LCM(12, 18) = 2^2 \times 3^2 = 36$
3. **Calculation**:
- $HCF \times LCM = 6 \times 36 = 216$
- Product of the numbers ($a \times b$) = $12 \times 18 = 216$
4. **Conclusion**:
Since $216 = 216$, the property is verified. The product of the HCF and LCM of two numbers is always equal to the **product of the numbers**.
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