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