Answer:
5 times
Explanation:
If we have to determine the number of times the lights will blink at the same time, we have to find Least common multiple (L.C.M) of 5, 12, and 6 seconds.
5 = 1 x 5
12 = 1 x 2 x 2 x 3
6 = 1 x 2 x 3
The L.C.M of 5, 6, and 12 is = 2 x 2 x 3 x 5 = 60
The three lights will be turned on after 60 seconds or 1 minute.
The lights will be turned on in 1 minute 1 time
The lights will be turned on in 5 minutes (1*5) times = 5 times