A lighthouse flashes at regular intervals: a long flash followed by two short ones, then a pause, repeating. A sailor knows this pattern encodes a two-letter signal in Morse, where a long is a dash and a short is a dot. What two-letter signal is the lighthouse sending?
Hints
Treat the long flash as dash and each short flash as dot, then match Morse letters before the pause.
Answer
The pattern is dash-dot-dot, which in Morse code is the letter 'D'. Since the cycle repeats 'D' twice before pausing, the lighthouse signal is 'DD'.