Question

A red light Flashes every 28 seconds.

A green light Flashes every 24 seconds.
They both Flash at the same time.
After how many seconds will they next both Flash at the same time?

Answer 1

Hi,

`LCM(28,24)=LCM(2^2*7,2^3*3)=2^3*3*7=168\ (s) \ or\ 2\min\ 48\ s`

Explanation:

Answer 2

2 min and 8 sec

Explanation:

LCM (28 , 24) = 186

The red and green light will flash together after every 168 seconds.

Time =168 / 60 MIN

Time = 2 minutes and 8 seconds