Question 2
Find the LCM and HCF of the following pairs of integers and verify that .
(i) and
(ii) and
(iii) and
UNDERSTAND THE QUESTION
The question asks to find the Least Common Multiple (LCM) and Highest Common Factor (HCF) for three pairs of integers. It also requires verifying the fundamental property of number theory that for any two positive integers and , the product of their LCM and HCF is equal to the product of the numbers themselves (). The core concepts required are prime factorization, identifying common factors, and basic arithmetic multiplication.
PART I
Find the LCM and HCF of 26 and 91 and verify that LCM × HCF = product of the two numbers.STEP 1 — PRIME FACTORIZATION OF THE NUMBERS
First, we determine the prime factorization of each number. For :
For :
STEP 2 — CALCULATE THE HCF
The HCF (or GCD) is the product of the lowest power of common prime factors. The common prime factor between and is .
STEP 3 — CALCULATE THE LCM
The LCM is the product of the highest power of all prime factors involved. The prime factors are .
STEP 4 — VERIFY THE PROPERTY
We verify that . Left Hand Side (LHS):
Right Hand Side (RHS):
Since LHS = RHS, the property is verified.
ANSWER
HCF = 13, LCM = 182. Verification: and .
PART II
Find the LCM and HCF of 510 and 92 and verify that LCM × HCF = product of the two numbers.STEP 1 — PRIME FACTORIZATION OF THE NUMBERS
First, we determine the prime factorization of each number. For :
For :
STEP 2 — CALCULATE THE HCF
The HCF is the product of the lowest power of common prime factors. The only common prime factor is . The lowest power is .
STEP 3 — CALCULATE THE LCM
The LCM is the product of the highest power of all prime factors involved. The prime factors are . Highest powers: .
STEP 4 — VERIFY THE PROPERTY
We verify that . Left Hand Side (LHS):
Right Hand Side (RHS):
Since LHS = RHS, the property is verified.
ANSWER
HCF = 2, LCM = 23460. Verification: and .
PART III
Find the LCM and HCF of 336 and 54 and verify that LCM × HCF = product of the two numbers.STEP 1 — PRIME FACTORIZATION OF THE NUMBERS
First, we determine the prime factorization of each number. For :
For :
STEP 2 — CALCULATE THE HCF
The HCF is the product of the lowest power of common prime factors. The common prime factors are and . Lowest power of is . Lowest power of is .
STEP 3 — CALCULATE THE LCM
The LCM is the product of the highest power of all prime factors involved. The prime factors are . Highest powers: .
STEP 4 — VERIFY THE PROPERTY
We verify that . Left Hand Side (LHS):
Right Hand Side (RHS):
Since LHS = RHS, the property is verified.