Question

Find the LCM and HCF of 15, 42 and 123

Answer 1

LCM - 1

HCF - 3

Explanation:

LCM - Lowest Common Factors

HCF - Highest Common Factors

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Factors of 15 - 1, 3, 5, 15

Factors of 42 - 1, 2, 3, 6, 7, 14, 21, 42

Factors of 123 - 1, 3, 41, 123

So now we know the factors of 15, 42, 123 what is lowest and highest factor we can find in every number

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I have bolded the lowest and highest common factor.

Factors of 15 - 1, 3, 5, 15

Factors of 42 - 1, 2, 3, 6, 7, 14, 21, 42

Factors of 123 - 1, 3, 41, 123

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LCM - 1

HCF - 3