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Question
Using prime factorization, find the HCF and LCM of 12,15, 21 .
Solution
12 = 2 × 2 × 3 = 22 × 3
15 = 3 × 5
21 = 3 × 7
HCF = product of smallest power of each common prime factor in the numbers = 3
LCM = product of greatest power of each prime factor involved in the numbers
= 22 × 3 × 5 × 7 = 420
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