LCM( 3, 5, 7, 5 ) = 105
Step 1: Write down factorisation of each number:
3 = 3
5 = 5
7 = 7
5 = 5
Step 2 : Match primes vertically:
3 | = | 3 | ||||
5 | = | 5 | ||||
7 | = | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
3 | = | 3 | ||||||
5 | = | 5 | ||||||
7 | = | 7 | ||||||
LCM | = | 3 | · | 5 | · | 7 | = | 105 |