SOLUTION: The red lights in an advertisement board blink every 3 seconds. The blue lights blink every 4 seconds and the green lights blink every 6 seconds. The three kinds of lights blinked

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Question 242981: The red lights in an advertisement board blink every 3 seconds. The blue lights blink every 4 seconds and the green lights blink every 6 seconds. The three kinds of lights blinked together at 7:00 p.m. After how many seconds will they blinked together again? How many times will they blink together in one minute?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The red lights in an advertisement board blink every 3 seconds. The blue lights blink every 4 seconds and the green lights blink every 6 seconds. The three kinds of lights blinked together at 7:00 p.m. After how many seconds will they blink together again? How many times will they blink together in one minute?
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Find the least common multiple of 3, 4, and 6.
LCM is 12.
Ans: 12 seconds after 7:00
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Ans: In one minutute they will blink together 60/12 = 5 times.
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Cheers,
Stan H.