Find the LCM and HCF of the following integers by applying the prime factorisation method.12, 15 and 21

Dear Student

Writing the product of prime factors for all the three numbers,
we get,

12=2×2×3
15=5×3
21=7×3

Therefore,
HCF(12,15,21) = 3
LCM(12,15,21) = 2× 2 × 3 × 5 ×7 = 420

Thanks