Find the HCF and LCM of 12, 15, 18, 27.

12 = 2 × 2 × 3

15 = 3 × 5


18 = 2 × 3 × 3


27 = 3 × 3 × 3


So HCF = 3


And LCM = product of prime factors with highest powers = 22 × 33 × 5 = 540


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