Question

Find the LCM and HCF of the following integers by applying the prime factorization method.

i) 12,15 and 21

ii) 17,23 and 29

iii) 8,9 and 25

Answer 1

i) 12,15 and 21

12=2×2×3

15=5×3

21=7×3

From the above ,HCF(12,15,21)=3and LCM(12,15,21)=420

ii)17,23,and 29

17=17×1

23=23×1

29=29×1

From the above ,HCF(17,23,29)=1and LCM(17,23,29)=11339

iii)8,9 and 25

8=2×2×2

9=3×3

25=5×5

From the above ,HCF(8,9,25)=1and LCM(8,9,25)=1800