Help!! I'm confused.

Answer:
12 seconds
Step-by-step explanation:
we need to find the Lcm which is 12
they both flash after 12 seconds
Answer:
Every 12 seconds
Step-by-step explanation:
You must find the LCM (Least common denominator)
4 x 3 = 12
Because 3 goes into 6 and 4 is four so the LCM is 12