Find the LCM and HCF of 12, 15 and 21 by applying the prime factorization method. [2 MARKS]
Prime factorisation : 1 Mark H.C.F : 0.5 Mark L.C.M : 0.5 Mark 212263
12 = 2×2×3
3155
15 = 3×5
3217
21 = 3×7
So H.C.F = 3
L.C.M = 420