Question

Find the LCM and HCF of the 12,15 and 21 integer by applying the prime factorisation method

Answer 1

420 is the lcm of 12 15 and 21

Answer 2

$\bf\huge\textbf{\underline{\underline{According\:to\:the\:Question}}}$  

LCM of 12 , 15 and 21

12 ⇒ 2 × 2 × 3 = 2^2 × 3^1

15 = 3 × 5

21 ⇒ 3 × 7

$\bf\huge\bf\huge{\boxed{\bigstar{{HCF=\:3}}}}$    

LCM = 2^2 × 3 × 5 × 7

= 4 × 3 × 5 × 7

$\bf\huge\bf\huge{\boxed{\bigstar{{420}}}}$