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Home » Using prime factorization, find the HCF and LCM of (i) 30, 72, 432 (ii) 21, 28, 36, 45
Using prime factorization, find the HCF and LCM of (i) 30, 72, 432 (ii) 21, 28, 36, 45
CBSE | Class 10 | Exercise 1B | Maths | Real Numbers | RS Aggarwal
Using prime factorization, find the HCF and LCM of (i) 30, 72, 432 (ii) 21, 28, 36, 45

Answers:

(i)

30 = 2 × 3 × 5

72 = 2 × 2 × 2 × 3 × 3 => 23 × 32

432 = 2 × 2 × 2 × 2 × 3 × 3 × 3 => 24 × 33

HCF = 2 × 3

HCF = 6

LCM = 24 × 33 × 5

LCM = 2160

(ii) 21 = 3 × 7

28 = 2 × 2 × 7 => 22 × 7

36 = 2 × 2 × 3 × 3 => 22 × 32

45 = 5 × 3 × 3 => 5 × 32

HCF = 1

LCM = 22 × 32 × 5 × 7

LCM = 1260

i

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