Question

A red blinking light blinks every 18 seconds, while a yellow blinking light blinks every 12 seconds. If both lights start at the same time, after how many seconds will they next blink at the same time? A) 6 B) 18 C) 36 D) 54

Answer 1

Least common multiple because that's when the numbers meet....... so the answer is C.

Answer 2

Option C, 36, because it is the LCM (Least common multiple)