LCM( 12, 24, 72, 75 ) = 1800
Step 1: Write down factorisation of each number:
12 = 2 · 2 · 3
24 = 2 · 2 · 2 · 3
72 = 2 · 2 · 2 · 3 · 3
75 = 3 · 5 · 5
Step 2 : Match primes vertically:
12 | = | 2 | · | 2 | · | 3 | ||||||||
24 | = | 2 | · | 2 | · | 2 | · | 3 | ||||||
72 | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | ||||
75 | = | 3 | · | 5 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
12 | = | 2 | · | 2 | · | 3 | ||||||||||
24 | = | 2 | · | 2 | · | 2 | · | 3 | ||||||||
72 | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | ||||||
75 | = | 3 | · | 5 | · | 5 | ||||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 5 | · | 5 | = | 1800 |