The light of a maritime lighthouse flashes every 180 seconds. Its green light flashes every 56 seconds. At midnight, both lights go off at the same time. Can they trigger again after 360s? Justify
Nope
For them to trigger again after 360 seconds, 56 must be a divisor of 180 (but , it isn't)
They will trigger again in
56 = 2^3 * 7
180 = 2^2 * 3^2 * 5
2^3 * 7 * 3^2 * 5 = 2520 seconds = 42 minutes
+16 
