Using prime factorization, find the HCF and LCM of:
i. 36, 84 ii. 23, 31
iii. 96, 404 iv. 144, 198
v. 396, 1080 vi. 1152, 1664
In each case, verify that:
HCF x LCM = product of given numbers.
i. HCF = 12, LCM = 252
Prime factorization of given numbers -
36 = 2 × 2 × 3 × 3
84 = 2 × 2 × 3 × 7
So HCF = product of common factors = 2 × 2 × 3 = 12
And LCM = product of prime factors with highest powers = 22 × 32 × 7 = 252
Verification -
HCF × LCM = product of numbers
⇒ LHS = 12 × 252 = 3024
⇒ RHS = 36 × 84 = 3024
∵ LHS = RHS(Hence verified)
ii. HCF = 1, LCM = 713
Prime factorization of given numbers -
23 = 23 × 1
31 = 31 × 1
So HCF = product of common factors = 1
And LCM = product of prime factors with highest powers = 23 × 31 = 713
Verification -
HCF × LCM = product of numbers
⇒ LHS = 1 × 713 = 713
⇒ RHS = 23 × 31 = 713
∵ LHS = RHS(Hence verified)
iii. HCF = 4, LCM = 9696
Prime factorization of given numbers -
96 = 2 × 2 × 2 × 2 × 2 × 3
404 = 2 × 2 × 101
So HCF = product of common factors = 2 × 2 = 4
And LCM = product of prime factors with highest powers = 25 × 3 × 101 = 9696.
Verification -
HCF × LCM = product of numbers
⇒ LHS = 4 × 9696 = 38784
⇒ RHS = 96 × 404 = 38784
∵ LHS = RHS(Hence verified)
iv. HCF = 18, LCM = 1584
Prime factorization of given numbers -
144 = 2 × 2 × 2 × 2 × 3 × 3
198 = 2 × 3 × 3 × 11
So HCF = product of common factors = 2 × 3 × 3 = 18
And LCM = product of prime factors with highest powers = 24 × 32 × 11 = 1584
Verification -
HCF × LCM = product of numbers
⇒ LHS = 18 × 1584 = 28512
⇒ RHS = 144 × 198 = 28512
∵ LHS = RHS(Hence verified)
v. HCF = 36, LCM = 11880
Prime factorization of given numbers -
396 = 2 × 2 × 3 × 3 × 11
1080 = 2 × 2 × 2 × 3 × 3 × 3 × 5
So HCF = product of common factors = 2 × 2 × 3 × 3 = 36
And LCM = product of prime factors with highest powers = 23 × 33 × 5 × 11 = 11880
Verification -
HCF × LCM = product of numbers
⇒ LHS = 36 × 11880 = 427680
⇒ RHS = 396 × 1080 = 427680
∵ LHS = RHS(Hence verified)
vi. HCF = 128, LCM = 14976
Prime factorization of given numbers -
1152 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3
1664 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 13
So HCF = product of common factors = 2 × 2 × 2 × 2 × 2 × 2 × 2 = 128
And LCM = product of prime factors with highest powers = 27 × 32 × 13 = 14976
Verification -
HCF × LCM = product of numbers
⇒ LHS = 128 × 14976 = 1916928
⇒ RHS = 1152 × 1664 = 1916928
∵ LHS = RHS(Hence verified)