LCM( 5, 2, 15, 30 ) = 30
Step 1: Write down factorisation of each number:
5 = 5
2 = 2
15 = 3 · 5
30 = 2 · 3 · 5
Step 2 : Match primes vertically:
5 | = | 5 | ||||
2 | = | 2 | ||||
15 | = | 3 | · | 5 | ||
30 | = | 2 | · | 3 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
5 | = | 5 | ||||||
2 | = | 2 | ||||||
15 | = | 3 | · | 5 | ||||
30 | = | 2 | · | 3 | · | 5 | ||
LCM | = | 2 | · | 3 | · | 5 | = | 30 |