Let's break all those down into prime factors: 27 = 3*3*3 45 = 3*3*5 60 = 2*2*3*5 72 = 2*2*2*3*3 96 = 2*2*2*2*2*3 Let's check to see which of those has the most 2 factors: 27 has 0 2's 45 has 0 2's 60 has 2 2's 72 has 3 2's 96 has 5 2's The most in that list is 5 2's. So the LCM has 5 2's 27 = 3*3*3 45 = 3*3*5 60 = 2*2*3*5 72 = 2*2*2*3*3 96 = 2*2*2*2*2*3 Let's check to see which of those has the most 3 factors: 27 has 3 3's 45 has 2 3's 60 has 1 3 72 has 2 3's 96 has 1 3's The most in that list is 3 3's. So the LCM has 5 2's and 3 3's 27 = 3*3*3 45 = 3*3*5 60 = 2*2*3*5 72 = 2*2*2*3*3 96 = 2*2*2*2*2*3 Let's check to see which of those has the most 5 factors: 27 has 0 5's 45 has 1 5 60 has 1 5 72 has 0 5's 96 has 0 5's The most in that list is 1 5. So the LCM has 5 2's, 3 3's, and 1 5. So LCM = 2*2*2*2*2*3*3*3*5 = 4320 Edwin