Question

Using prime factorisation, find the HCF and LCM of 8, 9, 25.

Answer 1

8 = 2 × 2 × 2 = 2³

9 = 3 × 3 = 3²

25 = 5 × 5 = 5²

HCF = product of smallest power of each common prime factor in the numbers = 1

LCM = product of greatest power of each prime factor involved in the numbers

= 2³ × 3² × 5²

= 1800