Question

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

12, 15 and 21

Answer 1

First, find the prime factors of the given integers: 15, 12 and 21 

For, 12 = 2 × 2 × 3 

15 = 3 × 5 

21 = 3 × 7 

Now, L.C.M of 12, 15 and 21 = 2 × 2 × 3 × 5 × 7 

∴ L.C.M (12, 15, 21) = 420 

And, H.C.F (12, 15 and 21) = 3