Divisibility and PrimesRace

Now we have a simple method for finding the lcm of two numbers:

1. Find the prime factorisation of each number.
2. Combine all prime factors, but only count duplicates once.

We can use the same method to find the lcm of three or more numbers at once, like 12, 30 and 45:

Therefore the lcm of 12, 30 and 45 is 2 × × 3 × 3 × = 180.