Question

HCF & LCM of 12 & 28

Answer 1

By applying Prime factorisation method

Prime factorisation of 12 and 28 :

$\star$12 = 2 × 2 × 3

$\star$28 = 2 × 2 × 7

Therefore , the LCM and HCF of these numbers are (2)² × 3 × 7 i.e 84 and 4

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By applying Euclid's division algorithm

Since , 12 > 28

$\to$We apply the division lemma to 12 and 28 , to get

28 = 12 × 2 + 4

$\to$Since , the remainder 4 ≠ 0 , we apply the divison lemma to 12 and 4 , to get

12 = 4 × 3 + 0

The remainder has now become zero , so our procedure stops . since the divisor at this stage is 4 , the HCF of 12 and 28 is 4