LCM of 2 3 and 5?

Answer 1

To get a common multiple, multiply the applicable numbers: 2*3*5 = 30

Next, look at any potential multiples less than that number to see if its the least common multiple. We'll look at five since it is the larget factor and therefore has the least number of multiples to look at.

5*1 = 5 Not divisible by 2 or 3

5*2 = 10 Not divisible by 3

5*3 = 15 Not divisible by 2

5*4 = 20 Not divisible by 3

5*5 = 25 Not divisible by 2 or 3

5*6 = 30 Divisible by 2, 3, and 5

The LCM is therefore 30

Alternatively you can look at the factoring of 30 (2*3*5, all prime numbers) and tell that there can't be a lower common multiple, but the above method is a more straightforward brute-force solution