Question

GCF & LCM word problems You might need: Calculator Two of the lights at the local stadium are flickering. They both just flickered at the same time. One of the lights flickers every 7 seconds and the other light flickers every 8 seconds. How many seconds until both lights will flicker at the same time again? seconds Show Calculator

Answer 1

To find how many seconds will it be until the lights flicker together again we have to find the lowest common multiple LCM of the times each light flickers.

Since one of them flickers every 7 seconds, and 7 is a prime number (it can only be divided by 7 and 1) and the other light flickers every 8 seconds and 8 is not a multiple of 7, then the LCM in this problem is the multiplication between these two numbers:

`8*7=56`

The lights will flicker again in 56 seconds