Question 15
In Beaver Bay, six lighthouses flash according to their own codes, shown below.
For example, lighthouse A has code 0100011010. In its first 10 seconds, its states are, in order: off, on, off, off, off, on, on, off, on, off. The same pattern repeats every 10 seconds. All six lighthouses start at the same time. At which of the following times are all their lights on?
For example, lighthouse A has code 0100011010. In its first 10 seconds, its states are, in order: off, on, off, off, off, on, on, off, on, off. The same pattern repeats every 10 seconds. All six lighthouses start at the same time. At which of the following times are all their lights on?