Question

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

Answer 1

LCM and HCF are

1) 12= 2×2×3

15=3×5

21=3×7

HCF=3

LCM= 2²×3×5×7

=2×2×3×5×7

=420

2) 17= 1×17

23= 1×23

29=1×29

HCF= 1

LCM=17×23×29

=11339

3) 8= 2×2×2

9=3×3

25=5×5

HCF=1

LCM= 1800