Question

how to find the LCM of 12 15 and 21​

Answer 1

Answer:

12, 15 and 21

The prime factors of the given numbers are

12 = 2 x 2 x 3 = 2² × 3¹

15 = 3 x 5 =3¹ × 5¹

21 = 3 x 7 =3¹ × 7¹

HCF of 12, 15 and 21

HCF of (12, 15 & 21) = 3

LCM of 12, 15 and 21

LCM of (12, 15 & 21) = 2² × 2¹ × 5¹ × 3¹ × 7¹

LCM of (12, 15 & 21) = 420