Least Common Multiple Math Example 4

Follow the full solution, then compare it with the other examples linked below.

easy

Two lights flash every

6

seconds and every

8

seconds. If they flash together now, after how many seconds will they flash together again?

1
Find the LCM of 6 and 8. Multiples of 6 are 6, 12, 18, 24; multiples of 8 are 8, 16, 24.
2
The first common multiple is 24, so the lights flash together again after 24 seconds.

Answer

24\text{ seconds}

The least common multiple gives the first time two repeating cycles line up again. It is the smallest shared multiple of both intervals.

About Least Common Multiple

The smallest positive integer that is divisible by each of two or more given numbers—where their multiples first coincide.

Find the LCM of [formula] and [formula].

Find the LCM of [formula], [formula], and [formula].

Find the LCM of [formula] and [formula].