Question 1093985: On a Christmas tree a first set of ligjts flashes every 3 seconds, a second set of lights flashes every 4 seconds and a third set of lights flaahes every 10 seconds. If the lights all came on at 10:00 am, at what time will they all come on together again?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! On a Christmas tree a first set of ligjts flashes every 3 seconds, a second set of lights flashes every 4 seconds and a third set of lights flaahes every 10 seconds.
If the lights all came on at 10:00 am, at what time will they all come on together again?
:
Find the least common multiple of 3, 4, 10
Prime factor
3: 3
4: 2*2
10: 2*5
LCM: 3*2*2*5 = 60 seconds. All light flash on at 10:01
:
:
At that time, 1st set flashes 20 times, the 2nd 15 times, the 3rd 6 times
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