On the coast there are 3 lighthouses. All 3 turn on at time zero.
- The first light shines for 3 seconds, then is off for 3 seconds.
- The second light shines for 4 seconds, and then is off for 4 seconds.
- The third light shines for 5 seconds, then is off for 5 seconds.

When is the first time all the lights will be off at the same time?

Posted by K Sengupta on 2024-02-06 11:45:03