Find the LCM and HCF of the following integers by applying the prime factorisation method: (i) 12, 15 and 21 (ii) 17, 23 and 29 (iii) 8, 9 and 25

Using prime factorisation method:
(i) 12, 15 and 21
Factor of 12 = 2×2×3
Factor of 15 = 3×5
Factor of 21 = 3×7
HCF(12,15,21) = 3
LCM(12,15,21) = 2×2×3×5×7 = 420
(ii) 17, 23 and 29
Factor of 17 = 1×17
Factor of 23 = 1×23
Factor of 29 = 1×29
HCF(17,23,29) = 1
LCM(17,23,29) = 1×17×23×29 = 11339
(iii) 8, 9 and 25
Factor of 8 = 2×2×2×1
Factor of 9 = 3×3×1
Factor of 25 = 5×5×1
HCF(8,9,25) = 1
LCM(8,9,25) = 2×2×2×3×3×5×5 = 1800