Question

Find out the LCM of the following numbers.

i. 9,15 

ii. 2,3,5 

iii. 12,28 

iv. 15,20 

v. 8,11

Answer 1

i. Multiples of 9 = 9, 18, 27, 36, 45, 54, 63, 72, 81, 90 

Multiples of 15 = 15, 30, 45 

∴ LCM of 9 and 15 = 45

ii. Multiples of 2 = 2, 4,6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 

Multiples of 3 = 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 

Multiples of 5 = 5, 10, 15, 20, 25, 30 

∴ LCM of 2,3 and 5 = 30

iii. Multiples of 12 = 12, 24, 36, 48, 60, 72, 84, 96, 108, 120 

Multiples of 28 = 28, 56, 84 

∴ LCM of 12 and 28 = 84

iv. Multiples of 15 = 15, 30, 45, 60, 75, 90, 105, 120 

Multiples of 20 = 20, 40, 60 

∴ LCM of 15 and 20 = 60

v. Multiples of 8 = 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96 

Multiples of 11 = 11, 22, 33, 44, 55, 66, 77, 88 

∴ LCM of 8 and 11 = 88