Question

What is the least common multiple of all positive integers smaller than 8?

Answer 1

420

Explanation:

Prime factorization:

7 = 7

6 = 2 × 3

5 = 5

4 = 2 × 2

3 = 3

2 = 2

1 = 1

LCM: 7, 6, 5, 4, 3, 2, 1

2 × 2 × 3 × 5 × 7 = 420

Answer 2

420

Explanation:

We need to find the LCM of 1, 2, 3, 4, 5, 6 and 7. The LCM of 1, 2, and 4 is 4 and the LCM of 3 and 6 is 6 so the list becomes the LCM of 4, 5, 6 and 7. The LCM of 4 and 5 is 20, the LCM of 20 and 6 is 60 and the LCM of 60 and 7 is 420.