You can put this solution on YOUR website! The sign flashed over 480 times in 1/2 hrs. How far apart did the flashes occur?
---
# of flashes per minute = 480 flashes/30 min = 16 flashes per min
---
Interval between flashes = 60 sec/16 flashes = 3.75 sec
==================================
Cheers,
Stan H.
===========