Question
Three lighthouses flash their lights every 15 seconds, 30 seconds and 40 seconds respectively. If they flash together at 7:13 p.m., at what time would the three lighthouses flash their lights together again?
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Three lighthouses flash their lights every 15 seconds, 30 seconds and 40 seconds respectively. If they flash together at 7:13 p.m., at what time would the three lighthouses flash their lights together again?